JP2020149017A - Image formation device - Google Patents

Abstract

To provide an image formation device that is excellent in a surface cleaning property of an image carrier under any of a high-temperature and high-humidity environment and a low-temperature and low-humidity environment.SOLUTION: An image formation device comprises: a photoreceptor 1Y that serves as one example of an image carrier; a charging roll that serves as one example of charging means; an exposure device that serves as one example of electrostatic image formation means; a developing device that serves as one example of developing means; a primary transfer roll, intermediate transfer belt and secondary transfer roll that serve as transfer means; a cleaning blade 60 that contacts with a surface of the photoreceptor 1Y; a photoreceptor cleaning device serves as one example of cleaning means cleaning the surface of the photoreceptor 1; and a fixing device that serves as one example of fixing means. In the image formation device, the cleaning blade 60 has a contact part 60A being a part contacting with the surface of the photoreceptor 1Y, in which JIS-A hardness of the contact part is equal to or more than 90 degrees and equal to or less than 130 degrees, and toner has a specific viscosity characteristic.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming apparatus.

Methods for visualizing image information via electrostatic charge images, such as electrophotographic methods, are currently used in various fields.
Conventionally, in the electrophotographic method, an electrostatic latent image is formed on the surface of a photoconductor by various means, and electrostatic detection particles called toner are attached to the electrostatic latent image (toner image). ) Is developed, transferred to the surface of the object to be transferred, and fixed by heating or the like, which is a method of visualizing the image.

In Patent Document 1, as a cleaning device used in an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine thereof to which an electrophotographic method is applied, deposits adhering to the surface of a member to be cleaned are removed by a cleaning blade. The cleaning blade is formed by laminating materials having different characteristics in a plurality of layers along the thickness direction, and constitutes a layer on the cleaning edge side that contacts a member to be cleaned of the cleaning blade. However, there is disclosed a cleaning device made of a high-hardness urethane resin, wherein the high-hardness urethane resin has a repulsive elasticity of 25% or less in a low temperature (10 ° C.) environment.

Patent Document 2 describes an electrophotographic toner containing a binder resin and a colorant, and the binding resin has a loss elastic modulus (G ″) from the glass transition temperature (Tg) of G ”= 1 × 10 ^4. The minimum value of tan δ of the binder resin exists between the temperatures of Pa, the minimum value of tan δ is less than 1.2, and the storage elastic modulus (G') at the minimum temperature of tan δ is G. Disclosed is an electrophotographic toner characterized by using a resin having a tan δ value of 3.0 or more at a temperature of'= 5 × 10 ⁵ Pa or more and G ”= 1 × 10 ⁴ Pa or more. Has been done.

Japanese Unexamined Patent Publication No. 2004-354527 JP-A-11-194542

There is a technique for improving the cleanability of the surface of the image holder by using a cleaning blade having a high hardness in contact with the image holder.
However, if a cleaning blade having a high hardness in contact with the image holder is simply used, depending on the physical properties of the toner (for example, viscoelasticity), it may be subjected to a high temperature and high humidity environment or a low temperature and low humidity environment. Good cleanability of the surface of the image holder may not be obtained.

The problem to be solved by the present invention is to set the toner viscosity η at T1 = 60 ° C. to η (T1), the toner viscosity η at T2 = 90 ° C. to η (T2), and the toner viscosity η at T3 = 130 ° C. When η (T3) is used, toner in which (lnη (T1) -lnη (T2)) / (T1-T2) exceeds −0.14, (lnη (T2) -lnη (T3)) / (T2-T3) ) Is less than −0.15, or the value of (lnη (T1) -lnη (T2)) / (T1-T2) is (lnη (T2) -lnη (T3)) / (T2-T3). Compared with the case of providing a developing means containing a statically charged image developer containing toner, which is less than or equal to the value of, the cleanability of the surface of the image holder in both a high temperature and high humidity environment and a low temperature and low humidity environment. It is to provide an excellent image forming apparatus.

Specific means for solving the above-mentioned problems include the following forms.
<1> Image holder and
The charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates a static charge image developer containing toner and develops the static charge image formed on the surface of the image holder as a toner image by the static charge image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A cleaning means having a cleaning blade that comes into contact with the surface of the image holder and cleaning the surface of the image holder.
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
With
The cleaning blade has a JIS-A hardness of 90 degrees or more and 130 degrees or less at a contact portion with the surface of the image holder.
In the toner, the viscosity η of the toner at T1 = 60 ° C. was η (T1), the viscosity η of the toner at T2 = 90 ° C. was η (T2), and the viscosity η of the toner at T3 = 130 ° C. was η (T3). When, (lnη (T1) -lnη (T2)) / (T1-T2) is -0.14 or less, and (lnη (T2) -lnη (T3)) / (T2-T3) is -0.15. As described above, the image forming apparatus in which (lnη (T2) -lnη (T3)) / (T2-T3) is a larger value than (lnη (T1) -lnη (T2)) / (T1-T2).

<2> Image forming apparatus <1> in which the cleaning blade has a laminated structure <3> The laminated structure has a JIS-A hardness of 90 degrees or more and 130 degrees or less, and JIS from the first layer and the first layer. Image forming apparatus <4> of <2> including a second layer having a small −A hardness The difference between the JIS-A hardness of the first layer and the JIS-A hardness of the second layer is 15 degrees or more. , <3>.
<5> Any one of <1> to <4>, wherein the pressure applied between the contact portion of the cleaning blade and the surface of the image holder is 2.0 g / mm or more and 3.2 g / mm or less. The image forming apparatus according to.

<6> When the viscosity η of the toner at T0 = 40 ° C. is η (T0), (lnη (T0) -lnη (T1)) / (T0-T1) is −0.12 or more. , (Lnη (T1) -lnη (T2)) / (T1-T2) and (lnη (T0) -lnη (T1)) / (T0-T1) are larger values <1> to <5> The image forming apparatus according to any one.
<7> The image forming apparatus according to any one of <1> to <6>, wherein the (lnη (T1) -lnη (T2)) / (T1-T2) in the toner is −0.16 or less. ..
<8> The image forming apparatus according to any one of <1> to <7>, wherein the (lnη (T2) -lnη (T3)) / (T2-T3) in the toner is −0.13 or more. ..
<9> The toner contains a release agent and contains
Any of <1> to <8>, where the aspect ratio of the release agent is 1.0 <a / b <8.0, where a is a number of 5 or more and b is a number less than 5. The image forming apparatus according to 1.
<10> The image according to <9>, where the aspect ratio of the release agent is 1.0 <c / d <4.0, where c is an area of 5 or more and d is an area of less than 5. Forming device.
<11> The image forming apparatus according to any one of <1> to <10>, wherein the maximum endothermic peak temperature of the toner is 70 ° C. or higher and 100 ° C. or lower.
<12> The image forming apparatus according to <11>, wherein the maximum endothermic peak temperature is 75 ° C. or higher and 95 ° C. or lower.
<13> The image forming apparatus according to any one of <1> to <12>, wherein the toner contains a styrene acrylic resin as a binder resin.
<14> The image forming apparatus according to any one of <1> to <12>, wherein the toner contains an amorphous polyester resin as a binder resin.

According to the invention according to <1>, <4>, <13>, or <14>, the toner in which (lnη (T1) -lnη (T2)) / (T1-T2) exceeds −0.14. , The toner in which (lnη (T2) -lnη (T3)) / (T2-T3) is less than −0.15, or the toner of the above (lnη (T1) -lnη (T2)) / (T1-T2). A high temperature and high humidity environment as compared with the case where a developing means containing a static charge image developer having a toner having a value of (lnη (T2) -lnη (T3)) / (T2-T3) or less is provided. An image forming apparatus having excellent cleanability on the surface of an image holder is provided in both a low temperature and a low humidity environment.

According to the invention according to <2>, the cleaning property of the surface of the image holder is excellent in both the high temperature and high humidity environment and the low temperature and low humidity environment as compared with the case of the cleaning blade having a single layer structure. An image forming apparatus is provided.
According to the invention according to <3>, as compared with the case where the first layer having a JIS-A hardness of 90 degrees or more and 130 degrees or less, the first layer, and the second layer having the same JIS-A hardness are provided. An image forming apparatus having excellent cleanability on the surface of an image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment.
According to the invention according to <4>, in a high temperature and high humidity environment, as compared with the case where the difference between the JIS-A hardness of the first layer and the JIS-A hardness of the second layer is less than 15 degrees. An image forming apparatus having excellent cleanability on the surface of the image holder is provided in both the low temperature and low humidity environment.
According to the invention according to <5>, the pressure applied between the contact portion of the cleaning blade and the surface of the image holder is less than 2.0 g / mm or more than 3.2 g / mm, as compared with the case where the pressure is less than 2.0 g / mm or more than 3.2 g / mm. An image forming apparatus having excellent cleanability on the surface of an image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment.

According to the invention according to <6>, a developing means containing a static charge image developer having a toner in which (lnη (T0) -lnη (T1)) / (T0-T1) is less than −0.12. An image forming apparatus having excellent cleanability on the surface of an image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment as compared with the case of providing the image holder.
According to the invention according to <7>, a developing means containing a static charge image developer having a toner in which (lnη (T1) -lnη (T2)) / (T1-T2) exceeds −0.16 is provided. An image forming apparatus having excellent cleanability on the surface of an image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment as compared with the case where the image holder is provided.
According to the invention according to <8>, a developing means containing a static charge image developer having a toner in which (lnη (T2) -lnη (T3)) / (T2-T3) is less than −0.13. An image forming apparatus having excellent cleanability on the surface of an image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment as compared with the case of providing the image holder.
According to the invention according to <9>, the case where a developing means containing a static charge image developer having a toner having a / b of 1.0 or less or 8.0 or more is provided is provided. In comparison, an image forming apparatus having excellent cleanability on the surface of the image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment.
According to the invention according to <10>, the case where a developing means containing a static charge image developer having a toner having a c / d of 1.0 or less or 4.0 or more is provided is provided. In comparison, an image forming apparatus having excellent cleanability on the surface of the image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment.
According to the invention according to <11> or <12>, when a developing means containing a static charge image developer having a toner having a toner having a maximum heat absorption peak temperature of less than 70 ° C. or more than 100 ° C. is provided. An image forming apparatus having excellent cleanability on the surface of the image holder is provided in both a high temperature and high humidity environment and a low temperature and low humidity environment.

It is a schematic block diagram which shows an example of the image forming apparatus which concerns on this embodiment. It is a schematic block diagram which shows an example of the cleaning means in this embodiment. It is a schematic block diagram which shows another example of the cleaning means in this Embodiment.

When referring to the amount of each component in the composition in the present specification, when a plurality of substances corresponding to each component are present in the composition, the plurality of kinds present in the composition unless otherwise specified. Means the total amount of substances in.
In the present specification, the "electrostatic image developer" is also simply referred to as a "developer".

Hereinafter, embodiments that are an example of the present invention will be described.

<Image forming device>
The image forming apparatus according to the present embodiment includes an image holder, a charging means for charging the surface of the image holder, and a static charge image forming means for forming a static charge image on the surface of the charged image holder. A developing means that accommodates a static charge image developer containing toner and develops a static charge image formed on the surface of the image holder as a toner image by the static charge image developer, and a surface of the image holder. A transfer means for transferring the formed toner image to the surface of the recording medium, a cleaning means having a cleaning blade in contact with the surface of the image holder and cleaning the surface of the image holder, and a surface of the recording medium. It is provided with a fixing means for fixing the toner image transferred to the image processing.
The cleaning blade in the cleaning means has a JIS-A hardness of 90 degrees or more and 130 degrees or less at the contact portion with the surface of the image holder.
Further, the developer contained in the developing means includes a toner viscosity η at T1 = 60 ° C. as η (T1), a toner viscosity η at T2 = 90 ° C. as η (T2), and a toner viscosity η at T3 = 130 ° C. When the viscosity η is η (T3), (lnη (T1) -lnη (T2)) / (T1-T2) is −0.14 or less, and (lnη (T2) -lnη (T3)) / ( T2-T3) is -0.15 or more, and (lnη (T2) -lnη (T3)) / (T2-T3) is higher than (lnη (T1) -lnη (T2)) / (T1-T2). Includes toner, which is a large value.
Hereinafter, the cleaning blade having the above-mentioned specific JIS-A hardness is also referred to as a "specific cleaning blade", and the toner having the above-mentioned characteristics is also referred to as a "specific toner".

The image forming apparatus according to the present embodiment is excellent in cleanability of the surface of the image holder in both a high temperature and high humidity environment and a low temperature and low humidity environment.
The reason can be inferred as follows.

First, the characteristics of the specific toner will be described. The above-mentioned formula (lnη (T1) -lnη (T2)) / (T1-T2) is an index showing the degree of change in the viscosity of the toner in the temperature range of 60 ° C. to 90 ° C., and this value is −0. When it is .14 or less, it means that the toner has a large change in viscosity in the range of 60 ° C. to 90 ° C. On the other hand, the above-mentioned formula (lnη (T2) -lnη (T3)) / (T2-T3) is an index showing the degree of change in the viscosity of the toner in the temperature range of 90 ° C. to 120 ° C., and this value is It is −0.15 or more, and (lnη (T2) -lnη (T3)) / (T2-T3) is larger than (lnη (T1) -lnη (T2)) / (T1-T2). This means that the toner has a small change in viscosity in the range of 90 ° C to 120 ° C. That is, the specific toner has a steep change in viscosity in the temperature range of 60 ° C. to 90 ° C., while the change in viscosity in the temperature range of 90 ° C. to 120 ° C. is small.
It is considered that the specific toner exhibiting such a characteristic of viscosity change contains both a low molecular weight component and a high molecular weight component in an appropriate ratio in the binder resin contained in the toner. That is, since the binder resin contains a low molecular weight component, the viscosity in the range of 60 ° C. to 90 ° C. tends to change easily, while the viscosity component in the binder resin tends to change from 90 ° C. to 120 ° C. This is thought to be because the viscosity tends to be difficult to change in the high temperature range of ° C.
It is considered that the specific toner exhibiting the characteristics of viscosity change as described above has a small change in viscosity and an appropriate viscoelasticity in the temperature range from room temperature (for example, 20 ° C.) to 60 ° C. That is, the specific toner contains a low molecular weight component and a high molecular weight component in an appropriate ratio in the binder resin, and the viscosity is less likely to change in the range of 60 ° C. or lower, and its viscoelasticity is also maintained in an appropriate range. It will be.

On the other hand, in the image forming apparatus, the image holder after transferring the toner image to the surface of the recording medium has the toner remaining on the surface of the image holder by bringing the cleaning blade into contact with the surface (hereinafter, residual toner). Cleaning such as) is performed. In particular, there is known a technique of using a cleaning blade having a high hardness in contact with the image holder to increase the scraping force of the cleaning blade and improve the cleanability of the surface of the image holder.
However, depending on the environment at the time of image formation such as a high temperature and high humidity environment or a low temperature and low humidity environment, sufficient cleaning property may not be obtained only by using the cleaning blade having increased scraping power as described above. ..
Specifically, in image formation in a high temperature and high humidity environment (for example, 28 ° C., 85% RH), if a toner having low viscoelasticity (which can be said to be a soft toner) is used, it remains on the surface of the image holder or the like. The toner is soft, and when the contact part with the image holder is in contact with the cleaning blade, which has a high hardness, further pressure is applied from the contact part with a high hardness, so that the adhesiveness of the residual toner increases and the residual toner becomes It sticks to the cleaning blade. If the residual toner adheres to the cleaning blade, the adhered toner is stretched between the adhered portion and the surface of the image holder, and adheres to the surface of the image holder in that state. As a result, image defects may occur due to poor cleaning of the surface of the image holder.
Further, in cleaning the surface of the image holder, a toner pool (also called a toner dam) due to residual toner is formed at a contact portion between the cleaning blade and the image holder. Residual toner stays in this toner pool and aggregates to prevent the residual toner from slipping between the image holder and the cleaning blade. In image formation in a low temperature and low humidity environment (for example, 10 ° C., 15% RH), a toner having high viscoelasticity (which can be said to be a hard toner) has a lower cohesiveness between the toners, and the cleaning blade and the image holder It is difficult for an appropriate toner pool to be formed at the contact portion. As a result, the residual toner slips through the cleaning blade and remains on the surface of the image holder, causing image defects.

In the image forming apparatus according to the present embodiment, a cleaning means using a cleaning blade having a JIS-A hardness of 90 degrees or more and 130 degrees or less at a contact portion with an image holder and the above-mentioned specific toner (that is, appropriate viscoelasticity) are used. It is provided with a developing means containing a developing agent containing a toner having a).
Since the specific toner is a toner having appropriate viscoelasticity as described above, it remains on the surface of the image holder, and even if the contact portion with the image holder comes into contact with a high hardness cleaning blade, the temperature is high. Adhesion to the surface of the photoconductor in a humid environment is easily suppressed, and slip-through from the cleaning blade in a low-temperature and low-humidity environment is easily suppressed.
Therefore, it is considered that the image forming apparatus according to the present embodiment is excellent in the cleanability of the surface of the image holder in both the high temperature and high humidity environment and the low temperature and low humidity environment.
Further, the specific toner exhibiting the characteristics of viscosity change as described above has a high viscosity on the toner surface on the fixing member side at the fixing portion, the toner image is easily peeled off from the fixing member, and the toner interface on the recording medium side. Is easily melted, and it is presumed that the toner is sufficiently easily permeated into the recording medium. Therefore, in the fixing portion, there are also effects such as the toner not sufficiently permeating into the recording medium, the toner image not peeling off from the fixing member, and the like, and the whiteout of the image is suppressed.
From the above, according to the image forming apparatus according to the present embodiment, image defects caused by poor cleaning of the image holder are suppressed in both a high temperature and high humidity environment and a low temperature and low humidity environment, and further, white. It is considered that an image with few omissions can be obtained.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers the toner image formed on the surface of the image holder to the recording medium; the toner image formed on the surface of the image holder is transferred to the intermediate transfer body. An intermediate transfer type device that first transfers to the surface and secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium; after the transfer of the toner image and before charging, static elimination light is applied to the surface of the image holder. A well-known image forming apparatus such as an apparatus provided with a static elimination means for irradiating and eliminating static electricity is applied.
In the case of an intermediate transfer type apparatus, the transfer means is, for example, an intermediate transfer body in which a toner image is transferred to the surface and a primary transfer in which a toner image formed on the surface of an image holder is primarily transferred to the surface of the intermediate transfer body. A configuration comprising means and secondary transfer means for secondary transfer of the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium is applied.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing means may have a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus.

Hereinafter, an example of the image forming apparatus according to the present embodiment will be described with reference to the drawings, but the present invention is not limited thereto. In the following description, the main parts shown in the figure will be described, and the description thereof will be omitted in the rest.

FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.
The image forming apparatus shown in FIG. 1 is a first electrophotographic system that outputs images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. A fourth image forming unit 10Y, 10M, 10C, 10K is provided. These image forming units (hereinafter, also simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged side by side at a predetermined distance from each other in the horizontal direction. These units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

Above each unit 10Y, 10M, 10C, 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 extends through each unit. The intermediate transfer belt 20 is provided by being wound around a drive roll 22 and a support roll 24 that are in contact with the inner surface of the intermediate transfer belt 20, and travels in a direction from the first unit 10Y to the fourth unit 10K. There is. A force is applied to the support roll 24 in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the support roll 24. An intermediate transfer belt cleaning device 30 is provided on the image holding surface side of the intermediate transfer belt 20 so as to face the drive roll 22. Further, on the image holding surface side of the intermediate transfer belt 20, a secondary transfer roll (an example of the secondary transfer means) 26 is provided so as to face the support roll 24.

Developing devices (examples of developing means) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K each contain a developer containing toner. Each of the developing devices 4Y, 4M, 4C, and 4K is supplied with the corresponding yellow, magenta, cyan, and black toners contained in the toner cartridges 8Y, 8M, 8C, and 8K.
The image forming apparatus according to the present embodiment uses a specific toner as at least one of the toners contained in the developing apparatus 4Y, 4M, 4C, 4K. From the viewpoint of improving the cleanability of the surface of the image holder, it is preferable that all the toners are specific toners.
Details of the specific toner and the developing means in which the developer having the specific toner is contained will be described later.
In the image forming apparatus shown in FIG. 1, the charging polarity of the toner is negative (−).

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration and operation, here, a yellow image arranged on the upstream side in the traveling direction of the intermediate transfer belt is formed. The unit 10Y of No. 1 will be described as a representative.
The image forming apparatus according to the present embodiment includes cleaning means having a specific cleaning blade as the photoconductor cleaning apparatus 6Y, 6M, 6C, 6K included in the first to fourth units 10Y, 10M, 10C, 10K. I am using it. From the viewpoint of improving the cleanability of the surface of the image holder, it is preferable that all of the photoconductor cleaning devices 6Y, 6M, 6C, and 6K are cleaning means having a specific cleaning blade.
Details of the cleaning means having the specific cleaning blade will be described later.

The first unit 10Y has a photoconductor 1Y, which is an example of an image holder.
Around the photoconductor 1Y, a charging roll (an example of charging means) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and a laser beam 3Y based on a color-separated image signal expose the charged surface. An exposure device (an example of a static charge image forming means) 3 for forming an electrostatic charge image, and a developing device (an example of a developing means) 4Y for developing a static charge image by supplying charged toner to the static charge image. A primary transfer roll (an example of a primary transfer means) 5Y that transfers a toner image onto an intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning means) that removes the toner remaining on the surface of the photoconductor 1Y after the primary transfer. 6Ys are arranged in order.

The primary transfer roll 5Y is arranged inside the intermediate transfer belt 20 and is provided at a position facing the photoconductor 1Y.
A bias power supply (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K of each unit. Each bias power supply changes the value of the transfer bias applied to each primary transfer roll by control by a control unit (not shown).

Hereinafter, the operation of forming a yellow image in the first unit 10Y will be described.
First, prior to the operation, the surface of the photoconductor 1Y is charged to a potential of −600 V to −800 V by the charging roll 2Y.
The photoconductor 1Y is formed by laminating at least a photosensitive layer on a conductive substrate (for example, a volume resistivity of 1 × 10 ^-6 Ωcm or less at 20 ° C.). This photosensitive layer usually has a high resistivity (resistance of a general resin), but has a property that when a laser beam is irradiated, the specific resistance of the portion irradiated with the laser beam changes. Therefore, the surface of the charged photoconductor 1Y is irradiated with the laser beam 3Y from the exposure apparatus 3 according to the image data for yellow sent from the control unit (not shown). As a result, an electrostatic charge image of the yellow image pattern is formed on the surface of the photoconductor 1Y.

The static charge image is an image formed on the surface of the photoconductor 1Y by charging. The laser beam 3Y reduces the specific resistance of the irradiated portion of the photosensitizer layer, and the charged charge on the surface of the photoconductor 1Y flows. On the other hand, it is a so-called negative latent image formed by the residual charge of the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoconductor 1Y rotates to a predetermined development position as the photoconductor 1Y travels. Then, at this developing position, the electrostatic charge image on the photoconductor 1Y is developed and visualized as a toner image by the developing device 4Y.

In the developing apparatus 4Y, for example, a static charge image developing agent containing at least yellow toner and a carrier is housed. The yellow toner is triboelectrically charged by being agitated inside the developing apparatus 4Y, has a charge having the same polarity (negative electrode property) as the charged charge on the photoconductor 1Y, and is a developer roll (developing agent holder). Example) It is held on. Then, as the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner is electrostatically adhered to the statically eliminated latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. Toner. The photoconductor 1Y on which the yellow toner image is formed is continuously traveled at a predetermined speed, and the toner image developed on the photoconductor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roll 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roll 5Y acts on the toner image. The toner image on the photoconductor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias (that is, the primary transfer bias) applied at this time is the polarity (+) opposite to the charging polarity (-) of the toner, and in the first unit 10Y, it is set to, for example, +10 μA by the control unit (not shown). It is controlled. The toner remaining on the photoconductor 1Y is removed by the photoconductor cleaning device 6Y and recovered.

The primary transfer bias applied to the primary transfer rolls 5M, 5C, 5K after the second unit 10M is also controlled according to the first unit.
In this way, the intermediate transfer belt 20 on which the yellow toner image is transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of each color are superimposed and multiplex transfer. Will be done.

The intermediate transfer belt 20 in which the toner images of four colors are multiplex-transferred through the first to fourth units includes the intermediate transfer belt 20, the support roll 24 in contact with the inner surface of the intermediate transfer belt, and the image holding surface of the intermediate transfer belt 20. It leads to a secondary transfer unit composed of a secondary transfer roll (an example of the secondary transfer means) 26 arranged on the side.
On the other hand, the recording paper (an example of the recording medium) P is fed through the supply mechanism into the gap (also referred to as the nip portion) where the secondary transfer roll 26 and the intermediate transfer belt 20 are in contact with each other at a predetermined timing. The next transfer bias is applied to the support roll 24. A bias power supply (not shown) for applying a secondary transfer bias is connected to the support roll 24. The bias power supply is controlled by a control unit (not shown), and outputs, for example, a secondary transfer bias having a (−) polarity that is the same as the charging polarity (−) of the toner.
Due to the secondary transfer bias applied to the support roll 24, the electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 20 is transferred onto the recording paper P.

The recording paper P on which the toner image is transferred is sent to the pressure contact portion (so-called nip portion) of the pair of fixing rolls in the fixing device (an example of the fixing means) 28, the toner image is fixed on the recording paper P, and the fixing image is fixed. Is formed. The recording paper P for which the color image has been fixed is carried out toward the ejection unit, and a series of color image forming operations is completed.

[Development means]
The developing means in the image forming apparatus according to the present embodiment accommodates a developing agent having a specific toner containing an external additive.
Specific examples of the developing means include a general developing apparatus that develops by bringing a developer into contact with or not in contact with an image holder.
The developing apparatus is not particularly limited as long as it has the above-mentioned functions, and is selected according to the purpose. For example, a known developing apparatus having a function of adhering a one-component developer or a two-component developer to a photoconductor using a brush, a roll, or the like can be mentioned. Of these, those using a developing roll in which the developing agent is held on the surface are preferable.

[Developer]
The developer contained in the developing means contains at least a specific toner. This developer may be a one-component developer containing only a specific toner, or may be a two-component developer containing a specific toner and a carrier.

(Specific toner)
The specific toner is composed of toner particles and, if necessary, an external additive.

(Viscosity characteristic value)
For the specific toner, the viscosity η of the toner at T1 = 60 ° C. was η (T1), the viscosity η of the toner at T2 = 90 ° C. was η (T2), and the viscosity η of the toner at T3 = 130 ° C. was η (T3). When
(Lnη (T1) -lnη (T2)) / (T1-T2) is −0.14 or less, and
(Lnη (T2) -lnη (T3)) / (T2-T3) is −0.15 or more, and
(Lnη (T2) -lnη (T3)) / (T2-T3) is a larger value than (lnη (T1) -lnη (T2)) / (T1-T2).
In addition, "lnη (T1)" in this disclosure is the value of the natural logarithm of the viscosity η of the toner at T1 = 60 ° C.
Further, the unit of the viscosity of the toner in the present disclosure is Pa · s unless otherwise specified.

The viscosity of the toner at each temperature (specifically, 130 ° C., 90 ° C., 60 ° C., and 40 ° C.) in the present embodiment means a value measured by the following method.
The viscosity of the toner in this embodiment is measured using a rotating flat plate rheometer (manufactured by Leometrics Scientific Co., Ltd .: RDA 2RHIOS system ver. 4.3.2). For the viscosity at each temperature, set a sample mass of about 0.3 g on a parallel plate with a diameter of 8 mm, apply a strain of 20% or less at a frequency of 1 Hz, and raise the temperature between about 30 ° C and 150 ° C at a rate of 1 ° C / min. When the temperature is raised in, the value measured at each temperature is used.

One of the characteristic values of the specific toner, (lnη (T1) -lnη (T2)) / (T1-T2), is −0.14 or less, and from the viewpoint of improving the cleanability of the surface of the image holder. It is preferably −0.16 or less, more preferably −0.30 or more and −0.18 or less, and particularly preferably −0.25 or more and −0.20 or less.
Further, one of the characteristic values of the specific toner, (lnη (T2) -lnη (T3)) / (T2-T3), is −0.15 or more, which is a viewpoint of improving the cleanability of the surface of the image holder. Therefore, it is preferably more than -0.14, more preferably -0.13 or more, further preferably -0.12 or more and -0.03 or less, and -0.11 or more and -0.05. The following is particularly preferable.
Further, in the specific toner, (lnη (T2) -lnη (T3)) / (T2-T3) is a larger value than (lnη (T1) -lnη (T2)) / (T1-T2), and the image is retained. From the viewpoint of improving the cleanability of the surface of the body, {(lnη (T2) -lnη (T3)) / (T2-T3)}-{(lnη (T1) -lnη (T2)) / (T1-T2)} The value of is preferably 0.01 or more, more preferably 0.05 or more and 0.5 or less, and particularly preferably 0.08 or more and 0.2 or less.

From the viewpoint of improving the cleanability of the surface of the image holder, the specific toner is obtained when the viscosity η of the toner at T0 = 40 ° C. is η (T0).
(Lnη (T0) -lnη (T1)) / (T0-T1) is −0.12 or more, and
It is preferable that (lnη (T0) -lnη (T1)) / (T0-T1) is larger than (lnη (T1) -lnη (T2)) / (T1-T2).

When (lnη (T0) -lnη (T1)) / (T0-T1) in the specific toner is −0.12 or more, the cleanability of the surface of the image holder is enhanced. (Lnη (T0) -lnη (T1)) / (T0-T1) is more preferably −0.05 or less, and particularly preferably −0.11 or more and −0.06 or less.
Further, in the specific toner, (lnη (T0) -lnη (T1)) / (T0-T1) is larger than (lnη (T1) -lnη (T2)) / (T1-T2). The cleanability of the surface of the image holder is improved. The value of {(lnη (T0) -lnη (T1)) / (T0-T1)}-{(lnη (T1) -lnη (T2)) / (T1-T2)} is 0.01 or more. It is preferably 0.05 or more and 0.5 or less, and particularly preferably 0.08 or more and 0.2 or less.

The characteristic values of the viscosity at each of these temperatures, that is, the above-mentioned (lnη (T1) -lnη (T2)) / (T1-T2), (lnη (T2) -lnη (T3)) / (T2-T3), The method of controlling the characteristic values relating to (lnη (T0) -lnη (T1)) / (T0-T1) within the above range is not particularly limited.
As a specific method, for example, the molecular weight of the binder resin contained in the toner particles is adjusted, and more specifically, the molecular weight values and contents of the low molecular weight component and the high molecular weight component of the binder resin are adjusted. There is a method of adjustment. Further, in the case of producing the toner particles by the agglutination coalescence method described later, a method of adjusting the degree of agglomeration by the amount of the aggregating agent added or the like can also be mentioned.

The specific toner is a toner viscosity η (T0) at T0 = 40 ° C., a toner viscosity η (T1) at T1 = 60 ° C., and a toner at T2 = 90 ° C. from the viewpoint of improving the cleanability of the surface of the image holder. It is preferable that the viscosity η (T2) and the viscosity η (T3) of the toner at T3 = 130 ° C. are in the following ranges, respectively.
Η (T0): 1.0 × 10 ⁷ ° C or higher and 1.0 × 10 ⁹ ° C or lower (more preferably 2.0 × 10 ⁷ ° C or higher and 5.0 × 10 ⁸ ° C or lower)
Η (T1): 1.0 × 10 ⁵ ° C or higher 1.0 × 10 ⁸ ° C or lower (more preferably 1.0 × 10 ⁶ ° C or higher 5.0 × 10 ⁷ ° C or lower)
Η (T2): 1.0 × 10 ³ ° C or higher 1.0 × 10 ⁵ ° C or lower (more preferably 5.0 × 10 ³ ° C or higher 5.0 × 10 ⁴ ° C or lower)
Η (T3): 1.0 × 10 ² ° C or higher 1.0 × 10 ⁴ ° C or lower (more preferably 1.0 × 10 ² ° C or higher 5.0 × 10 ³ ° C or lower)

(Maximum endothermic peak temperature)
The maximum endothermic peak temperature of the specific toner is preferably 70 ° C. or higher and 100 ° C. or lower from the viewpoint of easily controlling the viscosity of the toner, improving the cleanability of the surface of the image holder, and improving the fixability. , 75 ° C. or higher and 95 ° C. or lower, and particularly preferably 83 ° C. or higher and 93 ° C. or lower.
The maximum endothermic peak temperature of the specific toner is a temperature that gives the maximum endothermic peak in the endothermic curve including at least the range of −30 ° C. to 150 ° C. in the differential scanning calorimetry.
The method for measuring the maximum endothermic peak temperature of a specific toner is shown below.
A differential thermal scanning calorimeter DSC-7 manufactured by PerkinElmer Co., Ltd. is used, the melting points of indium and zinc are used to correct the temperature of the detection unit of the apparatus, and the heat of fusion of indium is used to correct the calorific value. An aluminum pan is used for the sample, an empty pan is set for the control, the temperature is raised from room temperature to 150 ° C. at a heating rate of 10 ° C./min, and the temperature is raised from 150 ° C. to -30 ° C. at a rate of 10 ° C./min. The temperature is lowered, and the temperature is further raised from −30 ° C. to 150 ° C. at a rate of 10 ° C./min, and the temperature of the largest endothermic peak at the time of the second temperature rise is defined as the maximum endothermic peak temperature.

(Infrared absorption spectrum of toner particles)
When the specific toner contains an amorphous polyester resin, which will be described later, as the binder resin, infrared absorption of the toner particles is performed from the viewpoint of easily controlling the viscosity of the toner and improving the cleanability of the surface of the image holder. the ratio of the absorbance at the wave number 1,500Cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 in the spectrum analysis (absorbance of absorption / wave number 720 cm ^-1 wavenumber 1,500cm ^-1) is, is 0.6 or less, and, wavenumber 720 cm the ratio of absorbance at wave number 820 cm ^-1 to the absorbance of ¹ (absorbance / absorbance at wave number 720 cm ^-1 wave number 820 cm ^-1) is preferably 0.4 or less. Further, the toner particles the ratio of the absorbance at the wave number 1,500Cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 in the infrared absorption spectrum analysis, is 0.4 or less, and the wave number 820 cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 the ratio of absorbance is more preferably 0.2 or less, the ratio of the absorbance at the wave number 1,500Cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 is, is 0.2 to 0.4, and, wavenumber 720 cm the ratio of absorbance at wave number 820 cm ^-1 to the absorbance of ^-1, and particularly preferably 0.05 to 0.2.

The absorbance of each wave number by infrared absorption spectrum analysis in this embodiment is measured by the following method.
First, a measurement sample is prepared from the toner particles to be measured (toner minus an external additive if necessary) by the KBr tablet method. Then, with respect to the measurement sample, an infrared spectrophotometer (manufactured by JASCO Corporation: FT-IR-410) is used to integrate 300 times and the resolution is 4 cm ^-1 , and the wave number is 500 cm ^-1 or more and 4,000 cm. ^-1 Measure the range below. Then, baseline correction is performed on the offset portion or the like where there is no absorbed light, and the absorbance of each wave number is obtained.

Also, in certain toner, it is preferable that the ratio of the absorbance at the wave number 1,500Cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles is 0.6 or less, is 0.4 or less More preferably, it is more preferably 0.2 or more and 0.4 or less, and particularly preferably 0.3 or more and 0.4 or less.
Furthermore, in certain toner, the ratio of absorbance at wave number 820 cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 in the infrared absorption spectrum analysis of the toner particles, it preferably 0.4 or less, 0.2 or less It is more preferably 0.05 or more and 0.2 or less, and particularly preferably 0.08 or more and 0.2 or less.

(Toner particles)
The toner particles contain, for example, a binder resin,, if necessary, a colorant, a mold release agent, and other additives. In particular, the toner particles preferably contain a binder resin and a mold release agent.
The toner particles may be, for example, toner particles such as yellow toner, magenta toner, cyan toner, and black toner, as well as white toner particles, transparent toner particles, and brilliant toner particles, and are not particularly limited.

-Bound resin-
Examples of the binder resin include styrenes (for example, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylic acid esters (for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid). n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (eg, acrylonitrile, Methacrylic acid, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (eg, vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene, butadiene, etc.) Examples thereof include homopolymers of monomers such as the above, and vinyl-based resins composed of copolymers in which two or more of these monomers are combined.
Examples of the binder resin include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures of these with the vinyl resins, or these. Examples thereof include a graft polymer obtained by polymerizing a vinyl-based monomer in the coexistence.
These binder resins may be used alone or in combination of two or more.

Among them, the binder resin is at least selected from the group consisting of styrene acrylic resin and amorphous polyester resin from the viewpoint of easily controlling the viscosity of the toner and improving the cleanability of the surface of the image holder. It is preferable to contain one kind, and it is more preferable to contain a styrene acrylic resin or an amorphous polyester resin. It is more preferable that the styrene acrylic resin or the amorphous polyester resin is contained in an amount of 50% by mass or more based on the total mass of the binder resin contained in the toner, and the styrene acrylic resin or the amorphous polyester resin is used. , 80% by mass or more is particularly preferable with respect to the total mass of the binder resin contained in the toner.
From the viewpoint of toner strength and storage stability, the specific toner preferably contains a styrene acrylic resin as the binder resin.
Further, the specific toner preferably contains an amorphous polyester resin as the binder resin from the viewpoint of low temperature fixability.
Further, the amorphous polyester resin is preferably an amorphous polyester resin having no bisphenol structure from the viewpoint of fixability.

(1) Styrene Acrylic Resin Styrene acrylic resin suitable as a binder resin is a styrene-based monomer (a monomer having a styrene skeleton) and a (meth) acrylic-based monomer (a single amount having a (meth) acrylic group). It is a copolymer obtained by at least copolymerizing a body, preferably a monomer having a (meth) acrylic group). The styrene acrylic resin contains, for example, a copolymer of a styrene monomer and the above-mentioned (meth) acrylic acid ester monomer.
The acrylic resin portion of the styrene acrylic resin has a partial structure obtained by polymerizing either or both of an acrylic monomer and a methacrylic monomer. Further, "(meth) acrylic" is an expression including both "acrylic" and "methacryl".

Specific examples of the styrene-based monomer include styrene and alkyl-substituted styrene (for example, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene). Ethylstyrene, 4-ethylstyrene, etc.), halogen-substituted styrene (for example, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc.), vinylnaphthalene, and the like can be mentioned. The styrene-based monomer may be used alone or in combination of two or more.
Among these, as the styrene-based monomer, styrene is preferable in terms of ease of reaction, ease of control of the reaction, and availability.

Specific examples of the (meth) acrylic monomer include (meth) acrylic acid and (meth) acrylic acid ester. Examples of the (meth) acrylic acid ester include (meth) acrylic acid alkyl ester (for example, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, n-propyl (meth) acrylic acid, n (meth) acrylic acid. -Butyl, n-pentyl (meth) acrylate, n-hexyl acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, (meth) acrylate n-dodecyl, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate, (meth) Isobutyl acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, amyl (meth) acrylate, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, (meth) ) Isooctyl acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, etc.), aryl (meth) acrylate (eg, phenyl (meth) acrylate, Biphenyl (meth) acrylate, diphenylethyl (meth) acrylate, t-butylphenyl (meth) acrylate, tarphenyl (meth) acrylate, etc.), dimethylaminoethyl (meth) acrylate, diethylamino (meth) acrylate Examples thereof include ethyl, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, β-carboxyethyl (meth) acrylate, and (meth) acrylamide. The (meth) acrylic acid-based monomer may be used alone or in combination of two or more.
Among the (meth) acrylic monomers, among these (meth) acrylic esters, from the viewpoint of fixability, the number of carbon atoms is 2 or more and 14 or less (preferably 2 or more and 10 or less carbon atoms, more preferably 3 or more). A (meth) acrylic acid ester having an alkyl group (8 or less) is preferable.
Of these, n-butyl (meth) acrylate is preferable, and n-butyl acrylate is particularly preferable.

The copolymerization ratio of the styrene-based monomer and the (meth) acrylic-based monomer (mass basis, styrene-based monomer / (meth) acrylic-based monomer) is not particularly limited, but is 85/15 or more. It is preferably 70/30.

The styrene acrylic resin preferably has a crosslinked structure from the viewpoint of toner strength and storage stability. The styrene acrylic resin having a crosslinked structure is preferably, for example, one obtained by at least copolymerizing a styrene-based monomer, a (meth) acrylic acid-based monomer, and a crosslinkable monomer.

Examples of the crosslinkable monomer include a bifunctional or higher functional crosslinker.
Examples of the bifunctional cross-linking agent include divinylbenzene, divinylnaphthalene, and di (meth) acrylate compounds (for example, diethylene glycol di (meth) acrylate, methylenebis (meth) acrylamide, decanediol diacrylate, glycidyl (meth) acrylate, etc.). , Polyester-type di (meth) acrylate, 2-([1'-methylpropyrine amino] carboxyamino) ethyl methacrylate and the like.
Examples of the polyfunctional cross-linking agent include tri (meth) acrylate compounds (for example, pentaerythritol tri (meth) acrylate, trimethylolethanetri (meth) acrylate, trimethylolpropane tri (meth) acrylate, etc.) and tetra (meth) acrylate. Compounds (eg, pentaerythritol tetra (meth) acrylate, oligoester (meth) acrylate, etc.), 2,2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, Examples thereof include triallyl trimellitate and diallyl chlorendate.
Among them, as the crosslinkable monomer, a bifunctional or higher functional (meth) acrylate compound is preferable, and a bifunctional (meth) acrylate compound is more preferable, from the viewpoint of toner strength, storage stability, and fixability. , A bifunctional (meth) acrylate compound having an alkylene group having 6 to 20 carbon atoms is more preferable, and a bifunctional (meth) acrylate compound having a linear alkylene group having 6 to 20 carbon atoms is particularly preferable.

The copolymerization ratio of the crosslinkable monomer to all the monomers (mass basis, crosslinkable monomer / total monomer) is not particularly limited, but is 2 / 1,000 to 20 / 1,000. Is preferable.

The glass transition temperature (Tg) of the styrene acrylic resin is preferably 40 ° C. or higher and 75 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower, from the viewpoint of fixability.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

From the viewpoint of storage stability, the weight average molecular weight of the styrene acrylic resin is preferably 5,000 or more and 200,000 or less, more preferably 10,000 or more and 100,000 or less, and particularly preferably 20,000 or more and 80,000 or less. ..

The method for producing the styrene acrylic resin is not particularly limited, and various polymerization methods (for example, solution polymerization, precipitation polymerization, suspension polymerization, bulk polymerization, emulsion polymerization, etc.) are applied. Further, a known operation (for example, batch type, semi-continuous type, continuous type, etc.) is applied to the polymerization reaction.

(2) Polyester Resin Examples of the polyester resin suitable as the binder resin include known amorphous polyester resins. As the polyester resin, a crystalline polyester resin may be used in combination with the amorphous polyester resin. However, the crystalline polyester resin may be used in a range of 2% by mass or more and 40% by mass or less (preferably 2% by mass or more and 20% by mass or less) with respect to the total binder resin.

The "crystallinity" of the resin means that the resin has a clear endothermic peak rather than a stepwise endothermic change in differential scanning calorimetry (DSC). Specifically, the temperature rise rate is 10 (° C.). / Min) indicates that the half-value width of the endothermic peak is within 10 ° C.
On the other hand, "amorphous" of the resin means that the half width exceeds 10 ° C., shows a stepwise endothermic amount change, or does not show a clear endothermic peak.

-Amorphous polyester resin Examples of the amorphous polyester resin include a condensed polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the amorphous polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.). , Alicyclic dicarboxylic acid (eg cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), these anhydrides, or their lower grades (eg, 1 or more carbon atoms). (5 or less) Alkyl ester can be mentioned. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, etc.). Hydrogenated bisphenol A, etc.), aromatic diols (for example, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be mentioned. Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a trihydric or higher multivalent alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
The polyhydric alcohol may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 65 ° C. or lower.
The glass transition temperature is obtained from the DSC curve obtained by differential scanning calorimetry (DSC), and more specifically described in JIS K 7121-1987 "Method for measuring transition temperature of plastics". It is obtained by the "external glass transition start temperature" of.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.
The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh GPC / HLC-8120GPC as a measuring device, a Tosoh column / TSKgel SuperHM-M (15 cm), and a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The amorphous polyester resin is obtained by a well-known production method. Specifically, for example, the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure inside the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a dissolution aid to dissolve the raw material. In this case, the polycondensation reaction is carried out while distilling off the dissolution aid. If a monomer having poor compatibility is present in the copolymerization reaction, the monomer having poor compatibility and the monomer are condensed with an acid or alcohol to be polycondensed in advance, and then weighted together with the main component. It is good to condense.

-Crystalline polyester resin Examples of the crystalline polyester resin include a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. As the crystalline polyester resin, a commercially available product may be used, or a synthetic resin may be used.
Here, since the crystalline polyester resin easily forms a crystal structure, a polycondensate using a polymerizable monomer having a linear aliphatic is preferable to a polymerizable monomer having an aromatic.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, and 1,10-decandicarboxylic acid. Acids, 1,12-dodecanedicarboxylic acids, 1,14-tetradecandicarboxylic acids, 1,18-octadecanedicarboxylic acids, etc., aromatic dicarboxylic acids (eg, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid) Examples thereof include dibasic acids such as acids), anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.
As the polyvalent carboxylic acid, a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure may be used in combination with the dicarboxylic acid. Examples of the trivalent carboxylic acid include aromatic carboxylic acids (for example, 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.). Anhydrides or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof can be mentioned.
As the polyvalent carboxylic acid, a dicarboxylic acid having a sulfonic acid group and a dicarboxylic acid having an ethylenic double bond may be used in combination with these dicarboxylic acids.
The polyvalent carboxylic acid may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include an aliphatic diol (for example, a linear aliphatic diol having 7 or more and 20 or less carbon atoms in the main chain portion). Examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-. Octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18- Examples thereof include octadecanediol and 1,14-eicosanedecanediol. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable.
As the polyhydric alcohol, a trihydric or higher alcohol having a crosslinked structure or a branched structure may be used in combination with the diol. Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.
The polyhydric alcohol may be used alone or in combination of two or more.

Here, the polyhydric alcohol preferably has an aliphatic diol content of 80 mol% or more, preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 60 ° C. or higher and 85 ° C. or lower.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for determining the melting temperature in JIS K 7121-1987 "Method for measuring transition temperature of plastics". ..

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

The crystalline polyester resin can be obtained by a well-known manufacturing method, like the amorphous polyester resin, for example.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and 60% by mass or more and 85% by mass or less with respect to the entire toner particles. More preferred.
When the toner particles are white toner particles, the content of the binder resin is preferably 30% by mass or more and 85% by mass or less, and more preferably 40% by mass or more and 60% by mass or less with respect to the entire white toner particles. ..

-Colorant-
Colorants include, for example, carbon black, chrome yellow, Hansa yellow, benzine yellow, slene yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, brilliant. Carmin 6B, Dupont Oil Red, Pyrazolon Red, Resole Red, Rhodamin B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultra Marine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malakite green oxalate, titanium oxide, zinc oxide, calcium carbonate, basic lead carbonate, zinc sulfide-barium sulfate mixture, zinc sulfide, silicon dioxide, aluminum oxide, etc., or aniline, xanthene, azo Various dyes such as benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole, etc. And so on.

When the toner particles are white toner particles, a white pigment may be used as the colorant.
As the white pigment, titanium oxide and zinc oxide are preferable, and titanium oxide is more preferable.

One type of colorant may be used alone, or two or more types may be used in combination.

As the colorant, a surface-treated colorant may be used if necessary, or may be used in combination with a dispersant. In addition, a plurality of types of colorants may be used in combination.

The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, and more preferably 3% by mass or more and 15% by mass or less with respect to the entire toner particles.
Further, when the toner particles are white toner particles, the content of the white pigment is preferably 15% by mass or more and 70% by mass or less, and more preferably 20% by mass or more and 60% by mass or less with respect to the entire white toner particles.

-Release agent-
Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montanic wax; ester waxes such as fatty acid esters and montanic acid esters. ; And so on. The release agent is not limited to this.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower, and 75 ° C. or higher and 95 ° C. or lower, from the viewpoint of the expression of releasability. It is more preferable that the temperature is 83 ° C. or higher and 93 ° C. or lower.
The melting temperature of the release agent is determined from the DSC curve obtained by differential scanning calorimetry (DSC), as described in "Melting peak" described in "Method for measuring transition temperature of plastics" of JIS K 7121-1987. Obtained by "temperature".

For the toner particles of the specific toner, the aspect ratio of the release agent in the toner is set to a number of 5 or more from the viewpoint of easily controlling the viscosity of the toner and improving the cleanability of the surface of the image holder. When the number less than 5 is b, 1.0 <a / b <8.0, preferably 1.0 <a / b <8.0, and 2.0 <a / b <7. It is more preferably 9.0, and particularly preferably 3.0 <a / b <6.0.
Further, from the viewpoint of easily controlling the viscosity of the toner and improving the cleanability of the toner particles of the specific toner, the aspect ratio of the release agent in the toner is c in an area of 5 or more and an area of less than 5. When d is, 1.0 <c / d <4.0 is preferable, 1.5 <c / d <3.5 is more preferable, and 2.0 <c / d <3. It is particularly preferably 0.0.

The aspect ratio of the release agent in the toner shall be measured by the following method.
Toner is mixed with the epoxy resin to solidify the epoxy resin. The obtained solidified product is cut by an ultramicrotome device (UltracutUCT manufactured by Leica) to prepare a flaky sample having a thickness of 80 nm or more and 130 nm or less. The flaky sample is then stained with ruthenium tetroxide in a desiccator at 30 ° C. for 3 hours. Then, an SEM image of the stained flaky sample is obtained with an ultra-high resolution field emission scanning electron microscope (FE-SEM) (for example, S-4800 manufactured by Hitachi High-Technologies Corporation). In general, the release agent is more easily stained with ruthenium tetroxide than the binder resin, so the release agent is identified by the shade depending on the degree of staining. If it is difficult to distinguish the shade due to the condition of the sample, adjust the staining time. In the cross section of the toner particles, the colorant domain is generally smaller than the release agent domain, so that it can be distinguished by the size.
When the SEM image includes toner particle cross sections of various sizes, a toner particle cross section having a diameter of 85% or more of the volume average particle diameter of the toner particles is selected, and 100 toners are randomly selected from the cross sections. Select a particle cross section and observe it. Here, the diameter of the toner particle cross section means the maximum length (so-called major axis) drawn at any two points on the contour line of the toner particle cross section.
In the SEM image, image analysis is performed on each of the 100 cross sections of the toner particles selected as described above under the condition of 0.010000 μm / pixel using image analysis software (WinROOF manufactured by Mitani Shoji Co., Ltd.). By this image analysis, an image of a cross section of the toner particles can be observed by the brightness difference (contrast) between the epoxy resin used for embedding and the binder resin of the toner particles. Based on the observed image, the length in the major axis direction, the length in the minor axis direction, and the aspect ratio (length in the major axis direction / length in the minor axis direction) of the release agent domain in the toner particles. , And the area can be determined.

As a method of adjusting the aspect ratio of the release agent in the toner, a method of growing crystals by holding the release agent at the temperature around the freezing point of the release agent for a certain period of time during cooling, and two or more types of release agents having different melting temperatures are used. This includes a method of promoting crystal growth during cooling.

The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the entire toner particles.

-Other additives-
Examples of other additives include well-known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as an internal additive.

-Characteristics of toner particles, etc.-
The toner particles may be toner particles having a single layer structure, or are toner particles having a so-called core-shell structure composed of a core portion (core particles) and a coating layer (shell layer) covering the core portion. You may.
Here, the toner particles having a core-shell structure include, for example, a core portion composed of a binder resin and, if necessary, other additives such as a colorant and a mold release agent, and a binder resin. It is preferably composed of a composed coating layer.

The volume average particle size (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

The volume average particle size of the toner particles is measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution is measured using ISOTON-II (manufactured by Beckman Coulter).
At the time of measurement, 0.5 mg or more and 50 mg or less of the measurement sample is added as a dispersant in 2 ml of a 5 mass% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm or more and 60 μm or less is obtained by using a 100 μm aperture with a Coulter Multisizer II. Measure. The number of particles to be sampled is 50,000.
The cumulative distribution of the volume is drawn from the small diameter side with respect to the particle size range (channel) divided based on the measured particle size distribution, and the particle size having a cumulative total of 50% is defined as the volume average particle size D50v.

The average circularity of the toner particles is not particularly limited, but is preferably 0.91 or more and 0.98 or less, and 0.94 or more and 0.98 or less from the viewpoint of improving the cleanability of the toner from the image holder. Is more preferable, and 0.95 or more and 0.97 or less are further preferable.

The average circularity of the toner particles is obtained by (circumferential peripheral length) / (peripheral length) [(circumferential length of a circle having the same projected area as the particle image) / (peripheral length of the particle projected image)]. Specifically, it is a value measured by the following method.
First, a flow-type particle image analyzer (for example,) that captures a particle image as a still image by sucking and collecting toner particles to be measured, forming a flat flow, and instantly emitting strobe light to analyze the particle image. , FPIA-3000 manufactured by Sysmex Co., Ltd. Then, the number of samplings when calculating the average circularity is set to 3500.
When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then ultrasonic treatment is performed to obtain toner particles from which the external additive has been removed. ..

The average circularity of the toner particles can be controlled, for example, by adjusting the stirring speed of the dispersion liquid, the temperature of the dispersion liquid, or the holding time in the fusion / coalescence step when the toner particles are produced by the aggregation / coalescence method. ..

(External agent)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.

The surface of the inorganic particles as an external additive should be hydrophobized. The hydrophobization treatment is performed, for example, by immersing the inorganic particles in a hydrophobizing agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane-based coupling agent, a silicone oil, a titanate-based coupling agent, and an aluminum-based coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethylmethacrylate (PMMA), and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, fluoropolymers). Particles) and the like.

The amount of the external additive added is preferably, for example, 0.01% by mass or more and 10% by mass or less, and more preferably 0.01% by mass or more and 6% by mass or less with respect to the toner particles.

(Toner manufacturing method)
Next, a method for producing the specific toner will be described.
The specific toner can be obtained by externally adding an external additive to the toner particles after manufacturing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method, etc.) and a wet production method (for example, an agglomeration coalescence method, a suspension polymerization method, a dissolution suspension method, etc.). The method for producing the toner particles is not particularly limited to these production methods, and a well-known production method is adopted.
Among these, it is preferable to obtain toner particles by the aggregation and coalescence method.

Specifically, for example, when the toner particles are produced by the aggregation and coalescence method,
A step of preparing a resin particle dispersion liquid in which resin particles to be a binder resin are dispersed (resin particle dispersion liquid preparation step) and a step of preparing the resin particle dispersion liquid and in the resin particle dispersion liquid (after mixing other particle dispersion liquids as necessary). (In the dispersion), resin particles (other particles if necessary) are agglomerated to form agglomerated particles (aggregated particle forming step), and the agglomerated particle dispersion in which the agglomerated particles are dispersed is heated. , Agglomerated particles are fused and coalesced to form toner particles (fusion and coalescence step), and toner particles are manufactured.

The details of each step will be described below.
In the following description, a method of obtaining toner particles containing a colorant and a mold release agent will be described, but the colorant and the mold release agent are used as needed. Of course, other additives other than colorants and mold release agents may be used.

-Resin particle dispersion liquid preparation process-
First, together with the resin particle dispersion liquid in which the resin particles to be the binder resin are dispersed, for example, a colorant particle dispersion liquid in which the colorant particles are dispersed and a release agent particle dispersion liquid in which the release agent particles are dispersed are prepared. To do.

Here, the resin particle dispersion liquid is prepared, for example, by dispersing the resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used in the resin particle dispersion liquid include an aqueous medium.
Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester salt type, sulfonate type, phosphoric acid ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol. Examples thereof include nonionic surfactants such as systems, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include general dispersion methods such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Further, depending on the type of resin particles, the resin particles may be dispersed in the resin particle dispersion liquid by, for example, a phase inversion emulsification method.
In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (O phase) to neutralize the resin, and then the aqueous medium is used. A method in which the (W phase) is charged to convert the resin from W / O to O / W (so-called phase inversion) to discontinue the phase, and the resin is dispersed in an aqueous medium in the form of particles. Is.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and further preferably 0.1 μm or more and 0.6 μm or less. preferable.
The volume average particle size of the resin particles is determined by using the particle size distribution obtained by the measurement of a laser diffraction type particle size distribution measuring device (for example, manufactured by Horiba Seisakusho, LA-700) with respect to the divided particle size range (channel). , The cumulative distribution is subtracted from the small particle size side for the volume, and the particle size that is cumulatively 50% of all particles is measured as the volume average particle size D50v. The volume average particle diameter of the particles in the other dispersion is also measured in the same manner.

The content of the resin particles contained in the resin particle dispersion is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

In addition, in the same manner as the resin particle dispersion liquid, for example, a colorant particle dispersion liquid and a release agent particle dispersion liquid are also prepared. That is, regarding the volume average particle size, dispersion medium, dispersion method, and particle content of the particles in the resin particle dispersion, the colorant particles dispersed in the colorant particle dispersion and the release agent particle dispersion are used. The same applies to the disperse of the release agent particles.

-Agglomerated particle formation process-
Next, the colorant particle dispersion and the release agent particle dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, the resin particles, the colorant particles, and the release agent particles are heteroaggregated to form the resin particles, the colorant particles, and the release agent particles having a diameter close to the diameter of the target toner particles. Form agglomerated particles containing.

Specifically, for example, a flocculant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, the pH is 2 or more and 5 or less), and a dispersion stabilizer is added as necessary. The particles are heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is -30 ° C or higher and the glass transition temperature is -10 ° C or lower), and the particles dispersed in the mixed dispersion are aggregated. To form aggregated particles.
In the agglomerated particle forming step, for example, the mixed dispersion is stirred with a rotary shear type homogenizer, the above-mentioned flocculant is added at room temperature (for example, 25 ° C.), and the pH of the mixed dispersion is acidic (for example, pH is 2 or more and 5 or less). ), And if necessary, a dispersion stabilizer may be added, and then the above heating may be performed.

Examples of the flocculant include a surfactant used as a dispersant added to the mixed dispersion, a surfactant having the opposite polarity, an inorganic metal salt, and a divalent or higher metal complex. In particular, when a metal complex is used as the flocculant, the amount of the surfactant used is reduced and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride and aluminum sulfate, and inorganics such as polyaluminum chloride, polyaluminum hydroxide and calcium polysulfide. Examples include metal salt polymers.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartrate acid, citric acid and gluconic acid, iminodic acid (IDA), nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA).
The amount of the chelating agent added is, for example, preferably 0.01 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.1 parts by mass or more and less than 3.0 parts by mass with respect to 100 parts by mass of the resin particles.

-Fusion / unification process-
Next, the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed is heated to, for example, a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature 10 to 30 ° C. higher than the glass transition temperature of the resin particles). Are fused and united to form toner particles.
Further, the agglomerated particles may be fused and coalesced to form toner particles by heating above the melting temperature of the release agent. In the fusion / union step, the resin and the release agent are in a fused state at the glass transition temperature of the resin particles or higher and the melting temperature of the release agent or higher. After that, it is cooled to obtain toner.
As a method of adjusting the aspect ratio of the release agent in the toner, a method of crystal growth by holding the release agent at the temperature around the freezing point of the release agent for a certain period of time during cooling, and two or more types of release agents having different melting temperatures are used. This includes a method of promoting crystal growth during cooling, and the like.

Toner particles are obtained through the above steps.
After obtaining the agglomerated particle dispersion liquid in which the agglomerated particles are dispersed, the agglomerated particle dispersion liquid and the resin particle dispersion liquid in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the agglomerated particles. The step of aggregating so as to adhere to form the second agglomerated particles and the second agglomerated particle dispersion liquid in which the second agglomerated particles are dispersed are heated to fuse and unite the second agglomerated particles. , Toner particles may be produced through the steps of forming toner particles having a core / shell structure.

Here, after the fusion / coalescence step is completed, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain toner particles in a dried state.
In the cleaning step, it is preferable to sufficiently perform replacement cleaning with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like may be performed from the viewpoint of productivity. The drying step is also not particularly limited, but from the viewpoint of productivity, freeze-drying, air-flow drying, fluid drying, vibration-type fluid drying and the like may be performed.

Then, the specific toner is produced, for example, by adding an external additive to the obtained dry toner particles and mixing them. The mixing may be carried out by, for example, a V blender, a Henschel mixer, a Ladyge mixer or the like. Further, if necessary, coarse particles of toner may be removed by using a vibration sieving machine, a wind sieving machine or the like.

(Career)
The carrier is not particularly limited, and examples thereof include known carriers.
As the carrier, for example, a coating carrier in which the surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder is impregnated with resin. Examples thereof include a resin-impregnated carrier.
The magnetic powder dispersion type carrier and the resin impregnated type carrier may be carriers in which the constituent particles of the carrier are used as a core material and coated with a coating resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid ester. Examples thereof include a copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polypropylene, a phenol resin, an epoxy resin and the like.
The coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include metals such as gold, silver and copper, and particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating with a coating resin and, if necessary, a coating layer forming solution in which various additives are dissolved in an appropriate solvent can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.
Specific resin coating methods include a dipping method in which the core material is immersed in a coating layer forming solution, a spray method in which the coating layer forming solution is sprayed on the core material surface, and a state in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and a solvent is removed.

The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

[Cleaning means]
The cleaning means in the present embodiment is a cleaning blade (that is, a specific cleaning blade) that is in contact with the surface of the image holder and has a JIS-A hardness of 90 degrees or more and 130 degrees or less at the contact portion with the surface of the image holder. Have and clean the surface of the image holder.

The cleaning means will be described with reference to the drawings.
FIG. 2 is a schematic configuration diagram showing a configuration of a cleaning blade in the photoconductor cleaning apparatus 6Y shown in FIG. 1 and an installation form thereof.
As described above, since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration and operation, the photoconductor cleaning device 6Y in the first unit 10Y is represented here. I will explain.

The photoconductor cleaning device 6Y has a cleaning blade 60 corresponding to the specific cleaning blade.
As shown in FIG. 2, the cleaning blade 60 includes a contact portion 60A that contacts the driven photoconductor 1Y to clean the surface of the photoconductor 1Y, and the contact portion 60A constitutes one side and drives the photoconductor 1Y. The tip surface 60B facing upstream in the direction (arrow A direction), the ventral surface 60C in which the contact portion 60A constitutes one side and faces the downstream side in the driving direction (arrow A direction) of the photoconductor 1Y, and the tip surface 60B. Non-contact angle which is a corner portion which shares one side with and faces the ventral surface 60C and faces the contact portion 60A on the front end surface 60B side, that is, a corner portion where the front end surface 60B and the back surface 60D are in contact with each other. It has a part 60E and.

The photoconductor cleaning device 6Y directs the surface of the cleaning blade 60 on one end side (that is, the tip surface 60B) in the direction facing the rotation direction (arrow A direction) of the photoconductor 1Y, and one corner portion (that is, the tip surface 60B) of the tip surface 60B. That is, the contact portion 60A) is brought into contact with the photoconductor 1Y to remove deposits such as residual toner on the surface.

Further, the cleaning blade 60 is joined to the support member 70 on the surface on the side in contact with the photoconductor 1Y, that is, the back surface 60D on the side opposite to the tip surface 60B, and is supported by the support member 70.
In FIG. 2, a metal support member 70 having an L-shape (for example, a metal material such as aluminum or stainless steel) is used.
In addition, an adhesive layer such as an adhesive for joining the adhesive between the support member 70 and the cleaning blade 60 may be provided.
A pressure member (not shown) is joined to the support member 70, and the cleaning blade 60 is pressed against the photoconductor 1Y by the pressure member via the support member 70.

[Pressing of cleaning blade]
The cleaning blade 60 is pressed against the photoconductor 1Y. The pressing pressure NF and the contact angle WA at that time will be described.

・ Pressing pressure NF
The pressing pressure of the cleaning blade 60 against the photoconductor 1Y (that is, the pressure applied between the contact portion 60A of the cleaning blade 60 and the surface of the photoconductor 1Y) is 2.0 gf / mm or more from the viewpoint of enhancing the cleaning performance. 2 gf / mm or less is preferable, 2.3 gf / mm or more and 3.2 gf / mm or less is more preferable, and 2.3 gf / mm or more and 2.9 gf / mm or less is further preferable.

・ Contact angle WA
The contact angle WA of the cleaning blade 60 with respect to the photoconductor 1Y is preferably 9 degrees or more and 12 degrees or less, more preferably 9.5 degrees or more and 12 degrees or less, and 10 degrees or more and 11.5 degrees or less from the viewpoint of improving cleaning performance. More preferred.

The pressing pressure NF and the contact angle WA of the cleaning blade 60 against the photoconductor 1Y are measured by the following methods.
First, a constant displacement is applied to the cleaning blade 60, the load is measured by the load cell, and the spring constant k peculiar to the cleaning blade 60 is obtained. Next, the cleaning blade 60 is fixed to the support member 70, and the position of the blade edge (that is, the angle including the contact portion 60A) is measured. A laser displacement meter or the like can be used for measuring the position. From the position of the blade edge, the bite amount d of the cleaning blade 60 when the photoconductor 1Y is brought into contact with the photoconductor 1Y is calculated. Then, the above values, the free length of the cleaning blade 60 (the length of the portion not fixed by the support member 70) L, and the set angle of the cleaning blade 60 (that is, the straight portion of the cleaning blade 60 (to the photoconductor 1Y) The pressing pressure NF and the contact angle WA are calculated from the following equations using the angle (angle) θ formed by the photoconductor 1Y and the portion that is not distorted by pressing.
Pressing pressure NF = k × d
Contact angle WA = θ-tan ^-1 (3d / 2L)

[Specific cleaning blade]
Subsequently, the specific cleaning blade will be described.
As described above, the specific cleaning blade is a plate-like object having a JIS-A hardness of 90 degrees or more and 130 degrees or less at the contact portion with the surface of the image holder, and there are no restrictions on other configurations.

(JIS-A hardness)
In the specific cleaning blade, the JIS-A hardness at the contact portion with the surface of the image holder (that is, the contact portion 20B in FIG. 2) is 90 degrees or more, so that the wear of the cleaning blade is suppressed, and further. The scraping force against the surface of the image holder is fully exerted. On the other hand, the specific cleaning blade has a JIS-A hardness of 130 degrees or less at the contact portion, which makes it difficult to damage the surface of the image holder, suppresses scratches on the surface of the image holder, and retains the image. Wear on the surface of the body is suppressed.
The JIS-A hardness at the contact portion of the specific cleaning blade is preferably 92 degrees or more and 98 degrees or less, and more preferably 93.5 degrees or more and 96.5 degrees or less.

Here, the JIS-A hardness of the cleaning blade is measured by the following method.
That is, according to the hardness test method shown in JIS K 6253 (1997), it is carried out using the type A durometer specified in JIS K 7215 (1986). Specifically, using a type A durometer (manufactured by a polymer measuring instrument) specified in JIS K 7215 (1986), a push needle (indenter) is pressed against the contact portion, and the maximum value of the pointer is read within 1 second. .. Then, this measurement is repeated 5 times, and the JIS-A hardness of the contact portion is obtained from the average value.

In order to control the JIS-A hardness in the contact portion within the above range, for example, in the resin used for the cleaning blade, a method of adjusting the combination of the hard segment material and the soft segment material, the hard segment material and the soft segment material. Examples thereof include a method of adjusting the material ratio (blending ratio) with and the method of adjusting the curing conditions (for example, aging time, temperature) when curing the resin used for the cleaning blade.
Further, a part of the cleaning blade may be modified by surface treatment or the like to form a contact portion having JIS-A hardness in the above range.
Further, the cleaning blade may have a laminated structure consisting of two or more layers, and one of the layers including the contact portion may be a layer having JIS-A hardness in the above range.

(material)
Examples of the material constituting the specific cleaning blade include an elastic material.
The material constituting the specific cleaning blade may contain a known additive in addition to the elastic material.

-Elastic material The elastic material is not particularly limited, and a conventionally known material is used. Examples of the elastic material include resin, and rubber is particularly preferable.
For example, examples of the elastic material include polyurethane rubber, silicone rubber, fluororubber, chloroprene rubber, butadiene rubber, and the like, and polyurethane rubber is particularly preferable.

Polyurethane rubber is usually synthesized by polymerizing polyisocyanate and polyol. Further, the polyurethane rubber may be synthesized by using a resin having a functional group capable of reacting with an isocyanate group in addition to the polyol. The polyurethane rubber preferably has a hard segment and a soft segment.
Here, the "hard segment" and the "soft segment" are made of a material in which the material constituting the former is relatively harder than the material constituting the latter in polyurethane rubber, and the material constituting the latter. The one means a segment made of a material that is relatively softer than the material that constitutes the former.

In polyurethane rubber, the combination of the material constituting the hard segment (that is, the hard segment material) and the material constituting the soft segment (that is, the soft segment material) is not particularly limited, and one is relatively hard with respect to the other. , The other can be selected from known resin materials so that the combination is relatively soft with respect to one. For example, the following combinations can be mentioned.
Polyurethane rubber is synthesized, for example, by polymerizing polyisocyanate and polyol. In addition to the polyol, a resin having a functional group capable of reacting with an isocyanate group may be used. It is desirable that the polyurethane rubber has a hard segment and a soft segment.
Here, the "hard segment" and the "soft segment" are materials in which the material constituting the former is relatively harder than the material constituting the latter among the polyurethane rubber materials, and the material constituting the latter. Means a segment made of a material that is relatively softer than the materials that make up the former.

The combination of the material constituting the hard segment (hard segment material) and the material constituting the soft segment (soft segment material) is not particularly limited, and one is relatively hard with respect to the other and the other is relative to the other. It can be selected from known resin materials so as to have a relatively soft combination, but in the present embodiment, the following combinations are preferable.

-Soft segment material As the soft segment material, a polyether polyol is preferably used. The polyether polyol is not particularly limited, and examples thereof include polyethylene glycol, polyoxytetramethylene glycol, polyoxypropylene glycol, and polycaprolactone polyol.
As the soft segment material, other polyols may be used, and examples of the polyol include a polyester polyol obtained by dehydration condensation of a diol and a dibasic acid, a polycarbonate polyol obtained by a reaction of a diol and an alkyl carbonate, and the like. ..
The soft segment material may be used alone or in combination of two or more.

-Hard segment material As the hard segment material, a chain extender is preferably used.
The chain extender is not particularly limited as long as it is conventionally known, and for example, 1,4-butanediol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexanediol, and 1,4-cyclohexane. Examples thereof include polyols having a molecular weight of 300 or less, such as diol, 1,4-cyclohexanedimethanol, xylene glycol, triethylene glycol, trimethylolpropane, glycerin, pentaerythritol, sorbitol, and 1,2,6-hexanetriol.
These may be used alone or in combination of two or more.

Alternatively, it is also desirable to use a resin having a functional group capable of reacting with an isocyanate group as the do-segment material. Further, it is desirable that the resin is flexible, and it is more desirable that the resin is an aliphatic resin having a linear structure from the viewpoint of flexibility. As a specific example, it is desirable to use an acrylic resin containing two or more hydroxyl groups, a polybutadiene resin containing two or more hydroxyl groups, an epoxy resin having two or more epoxy groups, or the like.
As a material constituting the hard segment, a polymer in which a cross-linking agent is further polymerized may be used.

When a hard segment material and a soft segment material are used, the mass ratio of the materials constituting the hard segment to the total amount of the hard segment material and the soft segment material (hereinafter referred to as "hard segment material ratio") is 10% by mass or more and 30% by mass. It is preferably in the following range, more preferably in the range of 13% by mass or more and 23% by mass or less, and further preferably in the range of 15% by mass or more and 20% by mass or less.

-Polyisocyanate Examples of the polyisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), 2,6-toluene diisocyanate (TDI), 1,6-hexanediisocyanate (HDI), and 1,5-naphthalenediocyanate (NDI). , And 3,3-dimethylbiphenyl-4,4-diisocyanate (TODI) and the like.
Of these, 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalenediisocyanate (NDI), and hexamethylene diisocyanate (HDI) are more desirable as the polyisocyanate.

The content of the polyisocyanate is preferably 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 35% by mass or less, and further preferably 20% by mass or more and 30% by mass or less with respect to the entire polyurethane rubber.

-Crosslinking agent Examples of the cross-linking agent include diol (bifunctional), triol (trifunctional), tetraol (tetrafunctional) and the like, and these may be used in combination.
Moreover, you may use an amine compound as a cross-linking agent. It is desirable that the product is crosslinked using a trifunctional or higher functional crosslinking agent. Examples of the trifunctional cross-linking agent include trimethylolpropane, glycerin, triisopropanolamine and the like.

The content of the cross-linking agent is preferably 2% by mass or less, more preferably 1.5% by mass or less, still more preferably 1.0% by mass or less, based on the entire polyurethane rubber. When the content of the cross-linking agent is in the above range, the molecular motion is less likely to be constrained by the chemical cross-linking as compared with the case where it is larger than the above range, and the required hardness can be easily obtained.

-Catalyst Examples of the catalyst include amine compounds such as tertiary amines, quaternary ammonium salts, and organometallic compounds such as organotin compounds.
Examples of the tertiary amine include trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N', N'-tetramethyl-1,3-butanediamine, and amino alcohols such as dimethylethanolamine. Esteramines such as ethoxylated amines, ethoxylated diamines and bis (diethylethanolamine) adipates, cyclohexylamine derivatives such as triethylenediamine (TEDA) and N, N-dimethylcyclohexylamines, N-methylmorpholin, N- (2-hydroxy) Examples thereof include morpholin derivatives such as propyl) -dimethylmorpholin, and piperazine derivatives such as N, N'-diethyl-2-methylpiperazine and N, N'-bis- (2-hydroxypropyl) -2-methylpiperazine.

Examples of the quaternary ammonium salt include 2-hydroxypropyltrimethylammonium octylate, 1,5-diazabicyclo [4.3.0] nonen-5 (DBN) octylate, and 1,8-diazabicyclo. [5.4.0] Undecene-7 (DBU) -octylate, DBU-oleate, DBU-p-toluenesulfonate, DBU-aterate, 2-hydroxypropyltrimethylammonium enterate, etc. Be done.

Examples of the organic tin compound include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di (2-ethylhexoate), first tin 2-ethylcaproate, and first tin oleate.

Among these catalysts, triethylenediamine (TEDA), which is a tertiary ammonium salt, is used in terms of hydrolysis resistance, and quaternary ammonium salt is preferably used in terms of processability. Among the quaternary ammonium salts, 1,5-diazabicyclo [4.3.0] nonen-5 (DBN) octylate and 1,8-diazabicyclo [5.4.0] undecene, which are highly reactive, 7 (DBU) -octylate and DBU-aterate are preferably used.

The content of the catalyst is preferably in the range of 0.0005% by mass or more and 0.03% by mass or less of the entire polyurethane rubber, and particularly preferably 0.001% by mass or more and 0.01% by mass or less.
These may be used alone or in combination of two or more.

The polyurethane rubber can be obtained, for example, by molding a composition obtained by blending the above-mentioned polyol (for example, hard segment material and soft segment material) with an isocyanate compound, a cross-linking agent, a catalyst, and the like.
The amount and ratio of polyol, polyisocyanate, cross-linking agent, and catalyst added should be adjusted within the required range.

The weight average molecular weight of the polyurethane rubber is preferably in the range of 1000 or more and 4000 or less, and more preferably in the range of 1500 or more and 3500 or less.
The weight average molecular weight is measured by gel permeation chromatography (GPC). Specifically, an HPLC 1100 manufactured by Tosoh Co., Ltd. is used as a measuring device, a column manufactured by Tosoh Co., Ltd., TSKgel GMHHR-M + TSKgel GMHHR-M (7.8 mm ID, 30 cm) is used, and measurement is performed using a chloroform solvent. The weight average molecular weight is calculated from this measurement result using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

-Form of cleaning blade The cleaning blade may have a single-layer structure as shown in FIG. 2 or may have a laminated structure as shown in FIG.
As shown in FIG. 3, when the cleaning blade 80 has a laminated structure, the JIS-A hardness is 90 degrees or more and 130 degrees or less, and the JIS-A hardness is smaller than that of the first layer 82 and the second layer 84. The difference between the JIS-A hardness of the first layer 82 and the JIS-A hardness of the second layer 84 is 15 degrees or more (preferably 15 degrees or more and 25 degrees or less, more preferably 15 degrees or more 18). It is more preferable that the degree is less than or equal to.
The first layer 82 shown in FIG. 3 is a layer including the contact portion 82A of the cleaning blade 80, and the second layer 84 is a layer including the non-contact angle portion 84E of the cleaning blade 80.
As described above, since the second layer is softer than the first layer, the second layer easily absorbs vibration due to friction at the contact portion with the photoconductor 1Y, and the contact posture of the cleaning blade with the surface of the photoconductor 1Y. Is more likely to be stabilized.

As yet another form, the cleaning blade has a single-layer structure as shown in FIG. 2, and only the portion in contact with the photoconductor 1Y (that is, the contact portion 60A in FIG. 2) is cured to cure JIS-A. It may be in the form of a contact portion having a hardness of 90 degrees or more and 130 degrees or less.

-Manufacture of Cleaning Blade A cleaning blade having a single-layer structure as shown in FIG. 2 is manufactured by, for example, the following method.
When the cleaning blade is composed of only a single-layer elastic member using polyurethane rubber, a general method for producing a polyurethane molded product such as a prepolymer method or a one-shot method is used.
The prepolymer method is suitable for the present embodiment because it can obtain a polyurethane molded product having excellent strength and abrasion resistance, but is not limited by the production method.

Specifically, the cleaning blade, which is a single-layer elastic member using polyurethane rubber, may be molded by mixing the above-mentioned polyol and polyisocyanate, and may further be blended with a chain extender, a cross-linking agent, or the like. ..
In addition, molding is produced by forming a composition for formation, which is blended and mixed as described above, into a sheet shape by using, for example, centrifugal molding, extrusion molding, etc., and performing cutting processing or the like. ..

Further, when the cleaning blade is composed of, for example, a thermoplastic resin, an injection molding machine or the like is used to extrude the thermoplastic resin melted by heating into a mold having a space corresponding to the shape of the cleaning blade. It may be produced by casting with a mold, then cooling and solidifying, and demolding.

Further, in the case of a cleaning blade having a laminated structure such as a two-layer structure as shown in FIG. 3, the first layer and the second layer are separately produced, and these are bonded to each other to produce a cleaning blade. ..
As a method of bonding the first layer and the second layer, double-sided tape, various adhesives and the like are preferably used.
Further, a plurality of layers may be bonded by pouring the materials of each layer into a mold at a time lag during molding and bonding the materials without providing an adhesive layer.

As a method of making the hardness (that is, JIA-A hardness) different between the first layer and the second layer, and a method of making the hardness of only the contact portion different from other regions, a method of making different materials and a resin There are a method of making the degree of polymerization different, a method of making the hardness different by performing a curing treatment, and the like.

Here, a method of making the hardness different by applying a hardening treatment will be specifically described.
Examples of the curing treatment include the following methods.
Plasma treatment is performed on the surface of the cleaning blade member to form a high-hardness film on the surface. Examples of the high hardness coating include DLC (diamond-like carbon). The coating film is as thin as 0.5 μm or more and 2.0 μm or less, and can secure the elasticity required for the member.

[recoding media]
The recording medium (recording paper P in the case of FIG. 1) for transferring the toner image may be, for example, plain paper used in an electrophotographic copier, a printer, or the like, or an OHP sheet, or plain paper. The surface of the paper may be coated with a resin or the like, an art paper for printing, or the like.

As the image forming apparatus according to the present embodiment, the image forming apparatus of the secondary transfer method has been described, but the present invention is not limited thereto.
The image forming apparatus according to the present embodiment may be a direct transfer type image forming apparatus.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples. In the following description, unless otherwise specified, "parts" and "%" are all based on mass.
The viscosity of the toner, the maximum endothermic peak temperature, and the absorbance at each wave number were measured by the methods described above.

(Developers A1 to A13 and B1 to B3)
-Preparation of styrene acrylic resin particle dispersion-
<Preparation of resin particle dispersion liquid (1)>
Styrene: 200 parts n-butyl acrylate: 50 parts Acrylic acid: 1 part β-carboxyethyl acrylate: 3 parts Propanediol diacrylate: 1 part 2-Hydroxyethyl acrylate: 0.5 parts Dodecanethiol: 1 part Anion in a flask A solution prepared by dissolving 4 parts of a sex surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) in 550 parts of ion-exchanged water was put therein, and a mixed solution containing the above raw materials was put therein and emulsified. While slowly stirring the emulsion for 10 minutes, 50 parts of ion-exchanged water in which 6 parts of ammonium persulfate was dissolved was added. Then, nitrogen substitution in the system was sufficiently performed, and the system was heated to 75 ° C. in an oil bath and polymerized for 30 minutes.

next,
Styrene: 110 parts n-butyl acrylate: 50 parts β-carboxyethyl acrylate: 5 parts 1,10-decanediol diacrylate: 2.5 parts Dodecanthiol: 2 parts Emulsify by adding a mixed solution of the above raw materials. , The emulsion was added to the above flask for 120 minutes, and the emulsion polymerization was continued for 4 hours as it was. As a result, a resin particle dispersion liquid in which resin particles having a weight average molecular weight of 32,000, a glass transition temperature of 53 ° C., and a volume average particle size of 240 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion liquid to adjust the solid content to 20% by mass to obtain a resin particle dispersion liquid (1).

<Preparation of resin particle dispersion liquid (2)>
Styrene: 200 parts n-Butyl acrylate: 50 parts Acrylic acid: 1 part β-carboxyethyl acrylate: 3 parts Propanediol diacrylate: 1 part 2-Hydroxyethyl acrylate: 0.5 parts Dodecanthiol: 1.5 parts In a flask , A solution prepared by dissolving 4 parts of an anionic surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) in 550 parts of ion-exchanged water was put therein, and a mixed solution containing the above raw materials was put therein and emulsified. While slowly stirring the emulsion for 10 minutes, 50 parts of ion-exchanged water in which 6 parts of ammonium persulfate was dissolved was added. Then, nitrogen substitution in the system was sufficiently performed, and the system was heated to 75 ° C. in an oil bath and polymerized for 30 minutes.

next,
Styrene: 110 parts n-butyl acrylate: 50 parts β-carboxyethyl acrylate: 5 parts 1,10-decanediol diacrylate: 2.5 parts Dodecanthiol: 2.5 parts Add the mixed solution containing the above raw materials. After emulsification, the emulsion was added to the above flask for 120 minutes, and the emulsion polymerization was continued for 4 hours as it was. As a result, a resin particle dispersion liquid in which resin particles having a weight average molecular weight of 30,000, a glass transition temperature of 53 ° C., and a volume average particle size of 220 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion liquid to adjust the solid content to 20% by mass to obtain a resin particle dispersion liquid (2).

<Preparation of resin particle dispersion liquid (3)>
Styrene: 200 parts n-Butyl acrylate: 50 parts Acrylic acid: 1 part β-carboxyethyl acrylate: 3 parts Propanediol diacrylate: 1 part 2-Hydroxyethyl acrylate: 0.5 parts Dodecanthiol: 1.5 parts In a flask , A solution prepared by dissolving 4 parts of an anionic surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) in 550 parts of ion-exchanged water was put therein, and a mixed solution containing the above raw materials was put therein and emulsified. While slowly stirring the emulsion for 10 minutes, 50 parts of ion-exchanged water in which 7 parts of ammonium persulfate was dissolved was added. Then, nitrogen substitution in the system was sufficiently performed, and the system was heated to 80 ° C. in an oil bath and polymerized for 30 minutes.

next,
Styrene: 110 parts n-Butyl acrylate: 50 parts β-carboxyethyl acrylate: 5 parts 1,10-decanediol diacrylate: 2.5 parts Dodecanthiol: 3.0 parts After emulsification, the emulsion was added to the flask for 120 minutes, and the emulsion polymerization was continued for 4 hours as it was. As a result, a resin particle dispersion liquid in which resin particles having a weight average molecular weight of 28,000, a glass transition temperature of 53 ° C., and a volume average particle size of 230 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion liquid to adjust the solid content to 20% by mass to obtain a resin particle dispersion liquid (3).

<Preparation of resin particle dispersion liquid (4)>
Styrene: 200 parts n-Butyl acrylate: 50 parts Acrylic acid: 1 part β-carboxyethyl acrylate: 3 parts Propanediol diacrylate: 1 part 2-Hydroxyethyl acrylate: 0.5 parts Dodecanthiol: 2.0 parts In a flask , A solution prepared by dissolving 4 parts of an anionic surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) in 550 parts of ion-exchanged water was put therein, and a mixed solution containing the above raw materials was put therein and emulsified. While slowly stirring the emulsion for 10 minutes, 50 parts of ion-exchanged water in which 7.5 parts of ammonium persulfate was dissolved was added. Then, nitrogen substitution in the system was sufficiently carried out, and the system was heated to 85 ° C. in an oil bath and polymerized for 30 minutes.

next,
Styrene: 110 parts n-butyl acrylate: 50 parts β-carboxyethyl acrylate: 5 parts 1,10-decanediol diacrylate: 2.5 parts Dodecanthiol: 3.5 parts Add the mixed solution containing the above raw materials. After emulsification, the emulsion was added to the flask for 120 minutes, and the emulsion polymerization was continued for 4 hours as it was. As a result, a resin particle dispersion liquid in which resin particles having a weight average molecular weight of 26,500, a glass transition temperature of 53 ° C., and a volume average particle size of 210 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20% by mass to obtain a resin particle dispersion (4).

<Preparation of resin particle dispersion liquid (5)>
Styrene: 200 parts n-butyl acrylate: 50 parts Acrylic acid: 1 part β-carboxyethyl acrylate: 3 parts Propanediol diacrylate: 1 part 2-Hydroxyethyl acrylate: 0.5 parts Dodecanthiol: 0.8 parts In a flask , A solution prepared by dissolving 4 parts of an anionic surfactant (Dowfax manufactured by Dow Chemical Co., Ltd.) in 550 parts of ion-exchanged water was put therein, and a mixed solution containing the above raw materials was put therein and emulsified. While slowly stirring the emulsion for 10 minutes, 50 parts of ion-exchanged water in which 5.5 parts of ammonium persulfate was dissolved was added. Then, nitrogen substitution in the system was sufficiently carried out, and the system was heated to 85 ° C. in an oil bath and polymerized for 30 minutes.

next,
Styrene: 110 parts n-butyl acrylate: 50 parts β-carboxyethyl acrylate: 5 parts 1,10-decanediol diacrylate: 2.5 parts Dodecane thiol: 1.7 parts Add a mixed solution containing the above raw materials. After emulsification, the emulsion was added to the flask for 120 minutes, and the emulsion polymerization was continued for 4 hours as it was. As a result, a resin particle dispersion liquid in which resin particles having a weight average molecular weight of 36,000, a glass transition temperature of 53 ° C., and a volume average particle size of 260 nm were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion liquid to adjust the solid content to 20% by mass to obtain a resin particle dispersion liquid (5).

<Preparation of magenta colored particle dispersion>
・ C. I. Pigment Red 122: 50 parts ・ Ion-based surfactant Neogen RK (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.): 5 parts ・ Ion-exchanged water: 220 parts The magenta colored particle dispersion (solid content concentration: 20%) was prepared by treating with 240 MPa for 10 minutes.

<Preparation of release agent particle dispersion (1)>
-Ester wax (WEP-2 manufactured by Nichiyu Co., Ltd.): 100 parts-Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2.5 parts-Ion exchange water: 250 parts Was mixed and heated to 120 ° C., dispersed using a homogenizer (Ultratarax T50 manufactured by IKA), and then dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin), and a release agent having a volume average particle size of 330 nm. A release agent particle dispersion liquid (1) (solid content 29.1%) in which particles were dispersed was obtained.

<Preparation of release agent particle dispersion (2)>
・ Fisher Tropschwax (HNP-9 manufactured by Nippon Seiko Co., Ltd.): 100 parts ・ Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2.5 parts ・ Ion-exchanged water: 250 parts The above materials are mixed, heated to 120 ° C., dispersed using a homogenizer (Ultratarax T50 manufactured by IKA), and then dispersed by a manton Gorin high-pressure homogenizer (manufactured by Gorin), and separated by a volume average particle size of 340 nm. A mold release agent particle dispersion liquid (2) (solid content 29.2%) in which mold particles were dispersed was obtained.

<Preparation of release agent particle dispersion (3)>
-Paraffin wax (FNP0090 manufactured by Nippon Seikan Co., Ltd.): 100 parts-Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2.5 parts-Ion exchange water: 250 parts The particles are mixed, heated to 120 ° C., dispersed using a homogenizer (Ultratarax T50 manufactured by IKA), and then dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin) to release agent particles having a volume average particle size of 360 nm. A release agent particle dispersion liquid (3) (solid content 29.0%) was obtained.

<Preparation of release agent particle dispersion (4)>
-Polyethylene wax (Polywax 725 manufactured by Toyo Adre Co., Ltd.): 100 parts-Anionic surfactant (Neogen RK manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 2.5 parts-Ion-exchanged water: 250 parts Was mixed and heated to 100 ° C., dispersed using a homogenizer (Ultratarax T50 manufactured by IKA), and then dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin), and a release agent having a volume average particle size of 370 nm. A release agent particle dispersion liquid (4) (solid content 29.3%) in which particles were dispersed was obtained.

<Manufacturing method of toner A1>
Ion-exchanged water: 400 parts Resin particle dispersion (1): 200 parts Magenta colored particle dispersion: 40 parts Release agent particle dispersion (2): 12 parts Release agent particle dispersion (3): 24 parts The above components Was placed in a reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and kept at a temperature of 30 ° C. and a stirring rotation speed of 150 rpm for 30 minutes while controlling the temperature from the outside with a mantle heater.
Disperse with a homogenizer (manufactured by IKA Japan Co., Ltd .: Ultratarax T50) and dissolve 2.1 parts of polyaluminum chloride (PAC, manufactured by Oji Paper Co., Ltd .: 30% powder product) in 100 parts of ion-exchanged water. PAC aqueous solution was added. Then, the temperature was raised to 50 ° C., and the particle size was measured with Coulter Multisizer II (aperture diameter: 50 μm, manufactured by Coulter) to set the volume average particle size to 5.0 μm. After that, 115 parts of the resin particle dispersion (1) was additionally added to attach the resin particles to the surface of the aggregated particles (shell structure).
Subsequently, 20 parts by mass of a 10% by mass NTA (nitrilotriacetic acid) metal salt aqueous solution (Kirest 70: manufactured by Kirest Co., Ltd.) was added, and then the pH was adjusted to 9.0 using a 1N sodium hydroxide aqueous solution. Then, the temperature was raised to 91 ° C. at a heating rate of 0.05 ° C./min and held at 91 ° C. for 3 hours, and then the obtained toner slurry was cooled to 85 ° C. and held for 1 hour. Then, it cooled to 25 degreeC to obtain magenta toner. This was further redispersed with ion-exchanged water and filtered repeatedly, washed until the electrical conductivity of the filtrate became 20 μS / cm or less, and then vacuum dried in an oven at 40 ° C. for 5 hours. To obtain toner particles.

For 100 parts of the obtained toner particles, 1.5 parts of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) were added. Was mixed at 10,000 rpm for 30 seconds using a sample mill. Then, the toner A1 was prepared by sieving with a vibrating sieve having an opening of 45 μm. The volume average particle size of the obtained toner A1 was 5.7 μm.

<Preparation of developer A1>
1: 8 parts of toner A and 92 parts of carrier: 92 parts were mixed by a V blender to prepare a developer A1 (electrostatic image developer A1).

<Preparation of developing agents A2 to A13, and B1 and B2>
Toners A2 to A13 are the same as toner A1, except that the resin particle dispersion liquid, mold release agent particle dispersion liquid, amount of coagulant, coalescence temperature, holding temperature, and holding time are changed as shown in Table 1. , And the magenta toners of toners B1 and B2, respectively.
Further, the developers A2 to A13 and the electrostatic charge image developing agents of the developing agents B1 and B2 were prepared in the same manner as the developing agent A1 except that the obtained toners were used respectively.

<Preparation of developer B3>
The magenta of toner B3 is the same as that of toner A1, except that the resin particle dispersion liquid, mold release agent particle dispersion liquid, coagulant amount, coalescence temperature, holding temperature, and holding time are changed as shown in Table 1. Obtained toner.
Further, an electrostatic charge image developer of the developer B3 was produced in the same manner as the developer A1 except that the obtained toner was used.

“A / b” in Table 1 is “a / b when the number of mold release agents having an aspect ratio of 5 or more is a and the number of mold release agents is less than 5 is b”, and is “c / d”. Is "c / d when the aspect ratio of the release agent is c for an area of 5 or more and d for an area of less than 5".

(Manufacturing of cleaning blades C1 to C3)
Cleaning blades C1 to C3 for installation in an electrophotographic copying machine described later were produced as follows.

<Manufacturing of cleaning blade C1>
A urethane resin having a JIS-A hardness of 90 degrees was molded by a centrifugal molding machine to prepare a cleaning blade C1.

<Creation of cleaning blade C2>
A urethane resin (low hardness material layer) having a JIS-A hardness of 80 degrees is formed by a centrifugal molding machine, and then a urethane resin (high hardness material layer) having a JIS-A hardness of 90 degrees is centrifugally formed on the urethane resin (high hardness material layer). A cleaning blade C2 was produced.

<Creation of cleaning blade C3>
A urethane resin (low hardness material layer) having a JIS-A hardness of 75 degrees is formed by a centrifugal molding machine, and then a urethane resin (high hardness material layer) having a JIS-A hardness of 90 degrees is centrifugally formed on the urethane resin (high hardness material layer). A cleaning blade C3 was produced.

[Examples 1-41 and Comparative Examples 1-9]
A commercially available electrophotographic copying machine (Docu Center Color450, manufactured by Fuji Xerox Co., Ltd.), which is an image forming apparatus equipped with a cleaning means using a cleaning blade, was prepared. The cleaning blades shown in Tables 2 to 4 were installed in this electrophotographic copying machine, and further, they were housed in the developing agents shown in Tables 2 to 4 in the developing apparatus.
Each cleaning blade was installed so that a region having a JIS-A hardness of 90 degrees or more was in contact with the photoconductor. The pressing pressure NF and the contact angle WA, which are the installation conditions of the cleaning blade, are as shown in Tables 2 to 4.

(Evaluation)
-Image formation in a high temperature and high humidity environment Using the electrophotographic copying machines of each example and comparative example, plain paper (manufactured by Fuji Xerox Co., Ltd., product name: P paper A4) in a high temperature environment (28 ° C, 85% RH). ), After outputting a 5000 pv (pv = number of image formation processed images (print volume)) image with an image density of 20%, one image with a full halftone of 50% was output.

-Image formation in a low temperature and low humidity environment Using the electrophotographic copying machines of each example and comparative example, plain paper (manufactured by Fuji Xerox Co., Ltd., product name: P paper A4) in a low temperature and low humidity environment (10 ° C, 15% RH). ), A 5000 pv (pv = number of image formation processed images (print volume)) image was output as an image with an image density of 1%, and then one image with 50% full halftone was output.

<Evaluation of adhesion of toner to the surface of the image holder (that is, photoconductor)>
The surface of each of the above two types of image-forming photoconductors was visually observed, and the degree of toner adhesion (that is, filming) to the photoconductor surface was evaluated according to the following criteria.
A: No adhesion of toner (that is, filming) was confirmed on the surface of the photoconductor.
B: Toner adhesion (that is, filming) was very slight on the surface of the photoconductor.
C: Toner adhesion (that is, filming) was generated in a streak pattern on the surface of the photoconductor.

<Confirmation of toner slip-through>
After attaching the cellophane tape to the surface of each of the above two types of image-forming photoconductors, peel it off, reattach the peeled cellophane tape to white paper, and apply the toner on the white paper. After confirmation, the degree of toner slipping was observed, and the degree of residual toner slipping was evaluated according to the following criteria.
A: No toner slipping was confirmed.
B: Slight slip-through of toner was confirmed.
C: Toner slip-through was confirmed over the entire cellophane tape.

<Evaluation of image defects>
The last image of the images output in each of the above two types of image formation was visually observed, and the degree of occurrence of image defects was evaluated according to the following criteria.
A: No image defects were confirmed.
B: Slight streaky image defects were confirmed.
C: Streaky image defects were confirmed.
D: Streaky image defects were clearly confirmed.

From Tables 2 to 4, (lnη (T1) -lnη (T2)) / (T1-T2) is −0.14 or less, and (lnη (T2) -lnη (T3)) / (T2-T3) is Satisfies the requirement that (lnη (T1) -lnη (T2)) / (T1-T2) is greater than −0.15 or more and (lnη (T2) -lnη (T3)) / (T2-T3). The image forming apparatus of each example using toner can be evaluated under high temperature and high humidity conditions and low temperature and low humidity environment as compared with the image forming apparatus of each comparative example using toner which does not satisfy at least one of these requirements. It can be seen that the toner does not adhere to the surface of the photoconductor and the toner does not slip through the cleaning blade, and image defects are suppressed.

(Developers A101 to A113 and B101 to B103)
-Preparation of amorphous polyester resin particle dispersion-
<Preparation of resin particle dispersion liquid (101)>
In a three-necked flask with the inside dried, 60 parts of dimethyl terephthalate, 74 parts of dimethyl fumarate, 30 parts of dodecenyl succinic anhydride, 22 parts of trimellitic acid, 138 parts of propylene glycol, and 0.3 parts of dibutyl tin oxide. In a nitrogen atmosphere, the water produced by the reaction was removed from the system and reacted at 185 ° C. for 3 hours. Then, the temperature was raised to 240 ° C. while gradually reducing the pressure, and the reaction was carried out for another 4 hours, and then cooled. In this way, an amorphous polyester resin (101) having a weight average molecular weight of 39,000 was prepared.

Next, 200 parts of the amorphous polyester resin (101) after removing the insoluble matter, 100 parts of methyl ethyl ketone, 35 parts of isopropyl alcohol, and 7.0 parts of a 10 mass% aqueous ammonia solution were placed in a separable flask. After sufficiently mixing and dissolving, ion-exchanged water was added dropwise at a liquid feeding rate of 8 g / min using a liquid feeding pump while heating and stirring at 40 ° C. After the liquid became uniformly cloudy, the phase was changed by increasing the liquid feeding speed to 15 g / min, and dropping was stopped when the liquid feeding amount reached 580 parts. Then, the solvent was removed under reduced pressure to obtain an amorphous polyester resin particle dispersion liquid (101) (resin particle dispersion liquid (101)). The volume average particle diameter of the obtained polyester resin particles was 170 nm, and the solid content concentration of the resin particles was 35%.

<Preparation of resin particle dispersion liquids (102) to (105)>
Resin particle dispersions (102) to (105) were obtained in the same manner as the resin particle dispersions (101) except that the conditions shown in Table 5 were changed.

<Manufacturing method of toner A101>
Ion-exchanged water: 400 parts Acrylic polyester resin particle dispersion (101): 200 parts Magenta colored particle dispersion: 40 parts Release agent particle dispersion (2): 12 parts Release agent particle dispersion (3): 24 parts The above-mentioned components were placed in a reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and kept at a temperature of 30 ° C. and a stirring rotation speed of 150 rpm for 30 minutes while controlling the temperature from the outside with a mantle heater.
Disperse with a homogenizer (manufactured by IKA Japan Co., Ltd .: Ultratarax T50) and dissolve 2.1 parts of polyaluminum chloride (PAC, manufactured by Oji Paper Co., Ltd .: 30% powder product) in 100 parts of ion-exchanged water. PAC aqueous solution was added. Then, the temperature was raised to 50 ° C., and the particle size was measured with Coulter Multisizer II (aperture diameter: 50 μm, manufactured by Coulter) to make the volume average particle size 4.9 μm. After that, 115 parts of the amorphous polyester resin particle dispersion liquid (101) was additionally added to attach the resin particles to the surface of the aggregated particles (shell structure).
Subsequently, 20 parts by mass of a 10% by mass NTA (nitrilotriacetic acid) metal salt aqueous solution (Kirest 70: manufactured by Kirest Co., Ltd.) was added, and then the pH was adjusted to 9.0 using a 1N sodium hydroxide aqueous solution. Then, the temperature was raised to 91 ° C. at a heating rate of 0.05 ° C./min and held at 91 ° C. for 3 hours, and then the obtained toner slurry was cooled to 85 ° C. and held for 1 hour. Then, it cooled to 25 degreeC to obtain magenta toner. This was further redispersed with ion-exchanged water and filtered repeatedly, washed until the electrical conductivity of the filtrate became 20 μS / cm or less, and then vacuum dried in an oven at 40 ° C. for 5 hours. To obtain toner particles.

For 100 parts of the obtained toner particles, 1.5 parts of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 1.0 part of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) were added. Was mixed and blended at 10,000 rpm for 30 seconds using a sample mill. Then, the toner A101 was prepared by sieving with a vibrating sieve having an opening of 45 μm. The volume average particle size of the obtained toner A101 was 5.8 μm.

<Preparation of developer A101>
8 parts of toner A101 and 92 parts of carrier: 92 parts were mixed by a V blender to prepare a developer A101 (electrostatic image developer A101).

<Preparation of developing agents A102 to A113, and B101 and B102>
Toners A102 to A113 are the same as toner A101, except that the resin particle dispersion liquid, mold release agent particle dispersion liquid, amount of coagulant, coalescence temperature, holding temperature, and holding time are changed as shown in Table 6. , And the magenta toners of the toners B101 and B102, respectively.
Further, the developers A102 to A113 and the electrostatic charge image developing agents of the developing agents B101 and B102 were prepared in the same manner as the developing agents A101 except that the obtained toners were used respectively.

<Preparation of developer B103>
The magenta of toner B103 is the same as that of toner A101, except that the resin particle dispersion liquid, mold release agent particle dispersion liquid, coagulant amount, coalescence temperature, holding temperature, and holding time are changed as shown in Table 6. Obtained toner.
Further, an electrostatic charge image developer of the developer B103 was produced in the same manner as the developer A101 except that the obtained toner was used.

“A / b” and “c / d” in Table 6 are the same as in Table 1, and “IR ratio (a)” is “absorbance of wave number 720 cm ^-1 in infrared absorption spectrum analysis of toner particles”. the ratio of the absorbance at the wave number 1,500Cm ^-1 for (i.e., wave number 1,500Cm absorbance / absorbance at wave number 720 cm ^{-1 -1)} ", and" IR ratio (b) "is the infrared absorption of the" toner particles the ratio of absorbance at wave number 820 cm ^-1 to the absorbance at a wavenumber of 720 cm ^-1 in the spectrum analysis (i.e., the absorbance of the absorbance / wave number 720 cm ^-1 wave number 820 cm ^-1) "it is.

[Examples 101-141 and Comparative Examples 101-109]
A commercially available electrophotographic copying machine (Docu Center Color450, manufactured by Fuji Xerox Co., Ltd.), which is an image forming apparatus equipped with a cleaning means using a cleaning blade, was prepared. The cleaning blades shown in Tables 7 to 9 were installed in this electrophotographic copying machine, and further, they were housed in the developing agents shown in Tables 7 to 9 in the developing apparatus.
The pressing pressure NF and the contact angle WA, which are the installation conditions of the cleaning blade, are as shown in Tables 7 to 9.

(Evaluation)
In the same manner as described above, images were formed in a high temperature and high humidity environment and a low temperature and low humidity environment, and the toner adhered to the surface of the photoconductor, the toner slipped through the cleaning blade, and the image defect was evaluated.

From Tables 7 to 9, (lnη (T1) -lnη (T2)) / (T1-T2) is −0.14 or less, and (lnη (T2) -lnη (T3)) / (T2-T3) is Satisfies the requirement that (lnη (T1) -lnη (T2)) / (T1-T2) is greater than −0.15 or more and (lnη (T2) -lnη (T3)) / (T2-T3). The image forming apparatus of each example using toner can be evaluated under high temperature and high humidity conditions and low temperature and low humidity environment as compared with the image forming apparatus of each comparative example using toner which does not satisfy at least one of these requirements. It can be seen that the toner does not stick to the surface of the photoconductor and the toner does not slip through the cleaning blade, and image defects are suppressed.

1Y, 1M, 1C, 1K photoconductor (example of image holder)
2Y, 2M, 2C, 2K charging roll (an example of charging means)
3 Exposure device (an example of electrostatic charge image forming means)
3Y, 3M, 3C, 3K laser beam 4Y, 4M, 4C, 4K developing device (example of developing means)
5Y, 5M, 5C, 5K primary transfer roll (example of primary transfer means)
6Y, 6M, 6C, 6K Photoreceptor cleaning device (an example of cleaning means)
8Y, 8M, 8C, 8K Toner Cartridge 10Y, 10M, 10C, 10K Image Formation Unit 20 Intermediate Transfer Belt (Example of Intermediate Transfer)
22 Drive roll
24 Support roll 26 Secondary transfer roll (an example of secondary transfer means)
28 Fixing device (an example of fixing means)
30 Intermediate transfer belt cleaning device (an example of intermediate transfer body cleaning means)
60 Cleaning blade 70 Support member 80 Cleaning blade P Recording paper (example of recording medium)

Claims (14)

Image holder and
The charging means for charging the surface of the image holder and
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image holder, and
A developing means that accommodates a static charge image developer containing toner and develops the static charge image formed on the surface of the image holder as a toner image by the static charge image developer.
A transfer means for transferring a toner image formed on the surface of the image holder to the surface of a recording medium, and
A cleaning means having a cleaning blade that comes into contact with the surface of the image holder and cleaning the surface of the image holder.
A fixing means for fixing the toner image transferred to the surface of the recording medium, and
With
The cleaning blade has a JIS-A hardness of 90 degrees or more and 130 degrees or less at a contact portion with the surface of the image holder.
In the toner, the viscosity η of the toner at T1 = 60 ° C. was η (T1), the viscosity η of the toner at T2 = 90 ° C. was η (T2), and the viscosity η of the toner at T3 = 130 ° C. was η (T3). When, (lnη (T1) -lnη (T2)) / (T1-T2) is -0.14 or less, and (lnη (T2) -lnη (T3)) / (T2-T3) is -0.15. As described above, the image forming apparatus in which (lnη (T2) -lnη (T3)) / (T2-T3) is a larger value than (lnη (T1) -lnη (T2)) / (T1-T2). The image forming apparatus according to claim 1, wherein the cleaning blade has a laminated structure. The image forming apparatus according to claim 2, wherein the laminated structure includes a first layer having a JIS-A hardness of 90 degrees or more and 130 degrees or less and a second layer having a JIS-A hardness lower than that of the first layer. The image forming apparatus according to claim 3, wherein the difference between the JIS-A hardness of the first layer and the JIS-A hardness of the second layer is 15 degrees or more. The method according to any one of claims 1 to 4, wherein the pressure applied between the contact portion of the cleaning blade and the surface of the image holder is 2.0 g / mm or more and 3.2 g / mm or less. Image forming device. When the viscosity η of the toner at T0 = 40 ° C. is η (T0), (lnη (T0) -lnη (T1)) / (T0-T1) is −0.12 or more, and (lnη). Any one of claims 1 to 5, wherein (lnη (T0) -lnη (T1)) / (T0-T1) is larger than (T1) -lnη (T2)) / (T1-T2). The image forming apparatus according to the section. The image forming apparatus according to any one of claims 1 to 6, wherein the (lnη (T1) -lnη (T2)) / (T1-T2) in the toner is −0.16 or less. The image forming apparatus according to any one of claims 1 to 7, wherein the (lnη (T2) -lnη (T3)) / (T2-T3) in the toner is −0.13 or more. The toner contains a release agent
Any of claims 1 to 8, wherein the aspect ratio of the release agent is 1.0 <a / b <8.0, where a is a number of 5 or more and b is a number less than 5. The image forming apparatus according to item 1. The image forming apparatus according to claim 9, wherein the aspect ratio of the release agent is 1.0 <c / d <4.0, where c is an area of 5 or more and d is an area of less than 5. The image forming apparatus according to any one of claims 1 to 10, wherein the maximum endothermic peak temperature of the toner is 70 ° C. or higher and 100 ° C. or lower. The image forming apparatus according to claim 11, wherein the maximum endothermic peak temperature is 75 ° C. or higher and 95 ° C. or lower. The image forming apparatus according to any one of claims 1 to 12, wherein the toner contains a styrene acrylic resin as a binder resin. The image forming apparatus according to any one of claims 1 to 12, wherein the toner contains an amorphous polyester resin as a binder resin.